This Reckless Design Flaw is Sinking Boats | Step 398

This is a discussion and reaction to the recent Arcona sailboat Sinking in the Pacific Ocean a few months ago.
Article: www.zeiltrends.nl/video-arcon...
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[@garychase8637]

as i am a retired broadcast engineer i have long felt television is not living up to its promise/use as an educational tool. the two of you have restored my faith in this concept, THANK YOU! add to this the fact that you both are natural teachers (my mother was one and you both remind me of her "style"". Please keep up the great work!!!

[@Roskellan]

TV is becoming an anchronism. It is not providing the content people want to watch, while it is politically and ideologicaly biased.

[@stopthephilosophicalzombie9017]

KZbin is actually the last bastion of knowledge transfer these days. The public school system has failed. Granted KZbin also censors a great deal of content which doesn't conform to the new woke orthodoxy, so it's a double edged sword.

[@dr.coole.]

Excellent rant. I really appreciate your explanations and learning opportunities. Rudders, compartments, bilges and pumps.

[@MarcoYolo420]

Loved it. Ill check the possibilities on my boat to separate 3 segments.

[@gangstagrandma]

It's always cool to see you two get into architect mode!

[@KevinMoyer]

Professional commercial mariner here, US tanker fleet for almost 20 years, life-long regatta kid and now cruiser, AND armchair-wannabe-naval architect (since I was a kid as well). THE BEST AND CONCISE AND EASY TO UNDERSTAND explanation (with visual aids!!!) of some really core, but overlooked, principles of naval arch. Nobody gets away from the engineering triangle, “High Quality, Fast Production, Low Expense…chose 2”. But you guys, your work, and your sharing is amazing! Long time subscriber and enjoy your work, helps inspire me on my boat jobs at home. Good luck as the refit continues!!!

[@stopthephilosophicalzombie9017]

I wouldn't be surprised if Dan (and/or Kika) went back to school for engineering degree. He's obviously got the aptitude.

[@enderdragoon]

I regularly mention in sailing communities that it's absurd to have an offshore boat that could potentially sink from rudder damage. A watertight bulkhead between the rudder and the rest of the boat is a critical design feature necessary for any boat to be considered blue water, IMO. Glad you're talking about this in detail.

[@TedKidd]

Particularly all this press about orcas taking out rudders....

[@SteinVarjord]

@@TedKiddAbout 3 boats have sunk from orca attacks around Spain. All of them sunk because of this stupid issue, missing bulkhead fwd of the rudder. Several others have been near by sinking, again from the same thing.

[@SteinVarjord]

I’ve also ranted about it innumerable times through decades. It astounds me that the builders don’t just do this right! It’s even very cheap. Must be some sort of immunity to brains and reason that is widespread among boat builders.

[@jeffdege4786]

Mine is a 1978 Vaitses/Herreshoff Meadowlark. The bulkhead that separates the cabin from the cockpit is watertight, creating two large compartments. I've not done the math to see if the boat would float with either one flooded.

[@jimfisk4474]

My gosh, what Info But you forgot one thing. And now I can't remember it.😂 I've never came across such Thoroughness. Thank you so much. For showing us how And bringing us along. Long time watcher and Listener. Take care and god bless.❤❤❤

[@brieneaton8578]

Canada here. Well said brother. That wasn't a rant. That was a lesson in " Buyer Beware ". And how to stay alive. Retired renovation carpenter. Love the both of you . And your work.

[@brandonboand]

As a 50 yr young American / Italian, I absolutely adore the both of you. I’m happy you’re back working on your sailboat and look forward to your continued adventures across the oceans. I’ve always loved the way you show other cultures and share your experiences and tell your stories. Such talented young couple! So much respect and admiration 🙏🏼❤️🙏🏼

[@SustainableSailing]

Our 1977 Rival 38 centre cockpit ketch didn't have any watertight bulkheads. As part of our big refit we have created multiple watertight compartments within the forecabin (plus entry to it that's above the waterline, will have a bolt close watertight door to use at sea). We are creating watertight compartments under the aft cabin bunk for rudder post (will leak a bit around the solid steering connection). Also a coffer dam around our 3 seacocks (2 cockpit drains 1 inlet for watermaker, deck wash etc) and propeller shaft (will leak a bit around the aquadrive).

[@MrSpinnerbug]

Dan, you did one excellent presentation on why water tight bulk heads are critical to be in any blue water boat! I think what you and Kika are doing is fantastic and you will have a super safe nice yacht when you are all done. It wasn’t a rant, rather an excellent , simplified explanation of the facts. Very well done! 😊🧐🧐⛵️

[@chilliconcarne8828]

I have an aluminum 28 ft sailboat which i bought several years ago. It is aged 56 years now and over some years I reinforced it with additional stringers and bulkheads. So now it has 6 watertight bulkheads which are placed corresponding to your ideas of fortifying a boat against water ingress. Even the skeg itself was enlarged and reinforced, because I don't sail regattas anymore but like singlehanded long distance sailing, where rudder agility is counterproductive. I hope that these modifications will be helpful in high latitude sailing which is on my bucket list for the next years. Fair winds to all of you sailing guys out there.

[@ms.chuckfu1088]

And following seas.

[@captainsalty56]

We have a Duncanson 43', a 35-year-old blue water cruiser. An Australian designed yacht built to survey standards. 5 watertight compartments including a crash bulkhead fore and aft. All fittings passing through a bulkhead are sealed with bulkhead glands. Even if the main saloon is awash the vessel will remain afloat. Yes, we have a skeg hung rudder, which was tested recently when we ripped off the bottom of the rudder. The skeg was totally undamaged. We sailed 100nm to the nearest lift out facility, lifted the boat, dropped and repairs the rudder in 19 days and continued sailing.

[@daveh.354]

This is along the lines of the lessons we should have learned from the Titanic. Gotta keep the water intrusions compartmentalized. I remember another youtube sailing channel discussing how a spade rudder hit something, bent backwards, and punched a hole right through the hull. It just surprises me that such a design is so prolific.

[@julianbatcheler9970]

It’s cheap and they play the numbers game. But yeah I want a skeg hung rudder.

[@gbexpatcornishman3004]

If I remember correctly, the Titanic did have watertight doors ... however, a 'glancing' collision and failure of riveted seams opened up 6 compartments to the sea. This exceeded her designed capacity to tolerate damage ... resulting in her sinking! Yours Aye GB

[@julianbatcheler9970]

@@gbexpatcornishman3004 the Titanic also had the issue that while watertight in most dimensions the bulkheads stopped at something like the forth deck down. So exactly what you are saying happened but also the bulkheads filled like a bucket and then that water overflowed via the top of the bulkheads from one to another.

[@Pocketfarmer1]

When you get to installing alarms , use several different types of voices for the alarms so you can tell them apart instantly.

[@timevans8223]

1980 Trintella 44. Front crash compartment. Chain locker is set back such that it is below the waterline. It keeps the weight of chain low and away from the bow. It drains with a 3/4" pipe to the main sump in the saloon. The main sump has a 2000gph bilge pump with an alarm that runs when the pump runs. In addition, there is is a 3700gpm emergency pump, a 2000gph shower bilge pump and a 1500gph engine bilge pump. The rudder is a 3 bearing skeg hung type behind a half height bulkhead. This also drains with a 3/4" pipe to the main saloon sump. The rudder shaft is s/s 90mm diameter at the centre bearing tapering to 60mm at each end to save weight. Built like a brick outhouse😀 the centre bearing is a bronze with a grease gun permanently attached. The rudder will be coming off this winter for the first time in 44 years. The boat has done 40,000nm in the last 10 years alone!

[@patrikohman4617]

This is like the best Pearson 36 Pearson never built. I really hope that Uma can sail into her registered home port :) It will be quite the homecoming :)

[@NomadicPhoton]

It would be so cool to see Uma in the Harbour City

[@ronkluwe4875]

You make excellent points in this video. I would like to add some input based on many years of offshore sailboat racing. Spade rudders can increase the capability of not sinking the boat by doing a couple of things and these are: 1) Use an internal rudder tube that is very strong and that goes between the inner hull and the cockpit deck. The rudder shaft rides on bearings in this tube; 2) Have the rudder shaft engineered so it is the weak link in the steering system so that if the boat hits something big enough to tear the rudder off, the shaft snaps and you lose the rudder, but not the boat; 3) Carry a spare rudder if you are going offshore. It doesn't take up as much space as you think and if you do lose a rudder (shaft being weak link), you can replace the rudder at sea; and 4) absolutely have a watertight bulkhead between the rudder shaft and the balance of the boat and try to make this watertight compartment as small as possible, even to the point of having a bulkhead before and after the rudder shaft. Another point is bilge pumps. Pretty much all, and I repeat all, bilge pumps installed in commercially manufactured sailboats are there only to remove nuisance water that may accumulate in the bilge. They typically have flow rates of less than 100 GPM (usually less than 50 GPM) and can be overwhelmed by losing a 1" diameter penetration point in the below waterline area. If you are serious about going offshore, look into getting a bilge pump, or bilge pumps, capable of 750 GPM to 1,000 GPM. These may not save the boat in a truly catastrophic incident, but may save the boat in a situation where you lose a hose or fitting on a hull penetration and need time to plug the water entry point. There are commercially available marine grade bilge pumps in this size range and they are not that expensive when compared to looking at total boat loss or having to abandon the boat in a deepwater situation.

[@guygillmore2970]

Having a means of shutting engine cooling inlet, detaching the hose and lowering it to the bilges is a good way of getting the engine water pump to pump out the bilges in a crisis is a good cheap fix

[@franklinnunley8405]

I have returned from facing my mortality and am so happy that you guys are still at it and doing so much for encouraging individualism and excellence in creating great entertainment at the same time, if we’re not careful we may learn something.

[@BJ-xs7np]

I never would have understood what you were talking about when you were talking about your bulkheads and sectioning off the boat with them until you went over that in this video. At the end of the video I said to myself, it all makes sense to me what they are doing and why. Thank you for using the other boats to explain it, because it now makes me think twice about sailboats and how they are built.

[@gbexpatcornishman3004]

On Torx Screws! Dear Sailing Uma, I followed you to Svalbard and back to Iceland ... and have 'dropped by' occasionally since. I have been woodworking for almost 50 years, undertaken a traditional wooden boatbuilding course in 2019 / 2020 and been building and repairing wooden railway carriages for the last 2 years. I studied aeronautical engineering at degree level, including a study of materials science, graduating over 30 years ago. I would strongly advise avoiding Torx screws in a marine environment! Stress Corrosion Cracking and Crevice Corrosion are both potential causes of the failure of stainless steel components in a marine environment. Not all Torx fasteners are created equal; can you guarantee that your Torx fasteners are A4 (316) grade stainless? That is more resistant to surface corrosion but the environmental conditions that fasteners experience - tensile stresses and low oxygen chlorine ion rich - are those that are more likely to result in failure. In addition to which, surface contamination of stainless steels with microscopic debris from plain carbon steel tools - screwdriver bits - can also encourage localised pitting corrosion. Furthermore, when it comes to future maintenance or repairs it is so much easier to clear debris, paint or sealant from a slotted screwhead than one with more complex form of socketed or recessed geometry such as Phillips, Posidriv, Square or Torx! Yours Aye GB

[@MonikaMatis]

the corrosion aspect is equally valid for any other type of screw so unless I am missing your point - it seems that only issue with TORX is the fact that they are harder to clean. Not something I would be bothered with too much, there are still methods allowing to clean them. But the transfer of torque by torx and slotted screws is simply difficult to compare - I am yet to get to the screw I cannot unscrew since I switched to torx headed ones. When I was using Philips I had around ten per each 150 used to epoxy in a hull panel. With slotted this number would go much higher still. So I guess the matter of cleaning the screw's head is secondary, because what is the point if the screw cannot transfer forces well enough to unscrew? ps. I agree on making sure all your bolts abd screws are A4. makes really huge difference. Fortunately there are specialised suppliers who can provide each type of steel in their fasteners so you can be sure to get all of them in chosen material.

[@stuartbrown5783]

Hi GB - like Monika I'm wondering why you have an issue with a ceratain type of screw head when the issue is fundamentally one of materials. Can you amplify your thoughts?

[@esvanes]

Tusen takk DK for this tip regarding watertight bulkheads. Beneteau Oceanis 500(1988). No watertight bulkheads in this boat. There is a bulkhead in front of the rudder, so it is possible to make this watertight, but a lot of cables and heating ducts going through this at the very bottom, so they must bee sealed of somehow. Also 12! Through hull fittings, but have replaced all of them with Trudesign this year. keep up your magnificent work.

[@SailingUma]

Yes. That’s usually the case. The bulkhead is there. But they just drill a dozen holes in it, which makes it useless.

[@myleshennell718]

we have a 5 year old 38.1 and it sounds like nothing has changed. I 'assumed' the bulkhead forward of the rudder stocks was watertight when I purchased and the decision to purchase was made, partly by this fact. I subsequently found that not to be the case as like yours, I found cable runs and heater ducting running through it, out of clear view from the watertight access port. It would not have taken much to seal these intrusions and significantly increase the safety. Keep up the great content please Team Uma, I look forward to seeing you back at the Southampton boat show as soon as your refit is complete :)

[@LifeOnTheHulls]

I have installed a sealed bulkhead forward of each of our rudder Bearings on my Catamaran to mitigate exactly this situation. I have also installed a bulkhead immediately behind our Rudder bearing tube and have attached the tube to the bulkhead to further support the stock, in the event of a collision the rudder stock will break instead of the gland and bearing. Great video again, really love your analysis. Rossco

[@SailingUma]

Sounds like great preventative work. Good job!!

[@bishopkinlyside8477]

Hi guys, wonderful to see Uma being put back together. I’m so glad you decided to restore her not to just do it abandon this wonderful yacht. Uma has such a wonderful character about her and it is your home on the ocean, and I’m so glad she’s going to be so safe without all those ups and downs with the hull Keep up the good work. Love and appreciate you both from Australia.

[@rickpetrinack1540]

Dan and Kika hi from Calgary. Dan best sailing channel rant ever. But seriously it all makes sense and you delivered a clear and informative message with passion. I just love how both of you approach a project, with a plan, proper preparation (eg shipping container workshop) logical solutions, not living on the boat while completing the refit, gutting the interior, confirming the issues, hiring professionals when required and hard work. Uma is going to be one helluva boat when its complete.

[@teddysdadcory]

Something to think about is how many, many years from now, if one or both of you starts to lose your memory, you will have all these wonderful videos to look back on to relive this adventure and share with future family and friends.

[@FireyFlyman]

PREACH!!! You have much wisdom to impart. Do it more!

[@TheMrBrianh]

I am so glad you decided to take the old companionway out. With everything else being nearly a clean slate, it makes sense to upgrade the "Front Door".

[@SustainableSailing]

In the UK we call those quarter berths. Here a pilot berth (these days) is above and outboard of the saloon settee (where most boats have storage shelves). Classic Nautor Swans have good examples of both.

[@rmccarthy175]

Love the water tight compartment explanation, and so handy that you’re in a boatyard with examples of the rudder types. 🤓

[@cohnee]

I was amazed to learn that the sort of watertight bulkheads are not common or even required for modern boats. A standard engineering safety design review should be driving those sorts of decisions. Great video (as always!)

[@dennisbell4542]

Much more explanitory videos like this please. This is the reason I have followed you from the beginning. Cheers, keep it up!

[@Mowikan]

Orca’s also like to play(attack)with the spade hang rudders….

[@SailingUma]

Yes. And sometimes sink boats for the same reason

[@theoldsailmaker6408]

​@@SailingUmacheck out Translated9(aSwan 65) where the skeg started ripping of without collision!! and lots of water got in the boat in the last OGR race(6month ago?) And old Swan's have a reputation for being super strong. So skeg helps for shure but you never know. All the best to you 2 . Thanks for all your great videos!

[@KenWallaceFilms]

I believe this is only happening in one specific part of the world (Strait of Gibraltar) with a specific pod of orcas, as opposed to being a typical orca behavior in general.

[@SailingAquamarine]

Orca attack any rudder, along the whole of the west coast Europe (Uk to Gibraltar.) If your rudder is fibreglass then it will be destroyed, if it is a spade rudder then likely you will have a big hole in the back of your boat as well.

[@gefginn3699]

Oh my goodness. You are almost to Step 400 ! Great Big Hugs ! 🌞⛵️🌴

[@JDarrow999]

I do not sail but I learned a lot today. Thank you very much for this great episode.

[@samwhitaker0]

Hilma Sailing lost their rudder somewhere in the middle of the Pacific back in 2018. It appears that Episode 45 features the ordeal with a few additional episodes discussing the aftermath.

[@ArtifexBarbarus]

Tapio Lehman’s recently sunk Golden Globe Racer had several supplemental professionally installed watertight bulkheads in place when it sank (out of the blue and within minutes). After the incident his marine architect investigated and decided the cause of the bulkhead failures was most likely inadequate care and consideration taken in their construction. Large quantities of water are *extremely* heavy and can generate *massive* forces in counterintuitive directions that can easily collapse lightly tabbed/under-braced bulkheads with disastrous consequence… Don’t scrimp on their construction!

[@timness1999]

Tapio Lahtinen was interviewed by the owner of Alluring Artic Sailing at kzbin.info/www/bejne/mGaTmYyYp7trmqc where he discusses the sinking of his S&S 33. In the pre-race video for the GGR Tapio explains the half dozen watertight bulkheads he put in to reduce the risk of sinking: kzbin.info/www/bejne/qYqvaZ2CpNx5eas. In the subsequent investigation his naval architects hypothesize the boat came down a wave landed on a container midships. Despite all of the watertight bulkheads the water ingress was so fast Tapio estimates the boat sank within about 6 minutes

[@PennWolfsSailingAdventures]

Lagoon is a perfect example of shortcuts and how ridiculous profit over quality is far too common.

[@unconventionalme8048]

17:47 daaaaannng! That was one long way around to explain something so simple

[@mumblbeebee6546]

My therapist is talking about “compartmentalisation” too 😎 Seriously, you are doing such a great job of making this fun to watch while doing serious stuff! Loving it!

[@rustyheyman214]

Two things you should always compartmentalize your life and your boat

[@orangelb]

With you two I have learned a lot and knowing that rebuilding a boat takes so much time, money and hard work, the training obtained by you is helping me enormously in the decision of which boat to acquire and what weaknesses and potential problems in each design. Thank you very much for the great contribution you guys give to all of us who are just starting out in this wonderful world of traveling on sailboats. Greetings and many hugs.

[@johnbecker1996]

Fantastic episode. As someone who's not conversant with boat design (or even sailing), it's great to hear about all the thought going into the refit.

[@kalimer0968]

I'm so exhausted by these titles..."don't hate the player. Hate the game.", I know, and I am. It's just been too much drama lately, no matter where I look.

[@verngay6557]

The joy of giving an old hull new life with new ideas was inspirational, this demo, refit with improvements of the first build is inspirational. Your fellow sailing families opted to have someone else build their dreams, you are using this time to educate others while providing piece of mind for yourselves. Great travel guides, story tellers, cinematographers, educators. Thank you for all.

[@svevergreen3370]

Pearson 424. No watertight compartments. One bilge 2 bilge pumps 2 independent lines for each. One high water sensor with a loud alarm and a bilge pump counter in the nav station to make sure somehow we get early warning. She has a skeg protected rudder like your Pearson, a very strong stock and packing gland arrangement and it is relatively small so the chance of it having enough "authority" to command the stock to make a hole in the rudder is very small. That said great idea to have a water tight compartment though !

[@richardmerrill4036]

I have watched Billy and Sierra plus Jason and Nikki with their new boats but I have more an interesting an informative experience watching you rebuild your boat. You two are very brave.

[@patrickfalter4487]

mad respect, just put my sailboat in the water after 5 weeks of straight work. Was getting fussy at the end mainly over other life pressures. You guys are top to bottom rebuilding your boat, thats a lot of work! Thank you for your content :)

[@PennySimone]

Some of the best answers to the question - "What makes a boat a blue water boat." Thank you.

[@andrewkeir2282]

Modern twin rudder monohulls have twin rudders because the beam at the stern is so wide, so when heeled a centerline rudder can come out of the water, wheras at twin rudder arrangement the rudder will be embedded deep in the water.

[@SailingUma]

Really!? Is that why? Or is that what they told you ;) What model and year Benny do you have? Salonas, Arconas and Defour all have similar transom widths and some of them use single centreline rudders.

[@brianluck84]

I've enjoyed almost all of your videos, that being said the construction videos are always my favorites.

[@0xKruzr]

perhaps underrated highlight of this episode: the Lifting Self Up Through Companionway Drama Noises courtesy of Dan and Kika.

[@Ryvar]

Great rant/teaching lesson, fantastic episode. One of your best ever on the building side.

[@petreamccarthy8635]

About time someone articulated this. Thanks for helping to publicise this issue I've been harping on about for years

[@mloret6745]

For the sail drive. Make an upside-down bucket with gasket and use over center pull latches that will crank the bucket down to the floor.

[@FromTheHeartOfRose]

Thank you for the lessons. I appreciate how you both share your knowledge and experience!

[@redensign9975]

Interesting tutorial on the bulkheads. With multiple bulkheads you should be just as unsinkable as the Titanic. 😆😅😂🤣

[@Cptnbond]

Yes Titanic had lots of bulkheads, unfortunately the iceberg ripped the hull along the ship side, which is what (likely) a steel container will do on a GRP boat as well.

[@jeffreyparker587]

Another problem with the titanic is the watertight bulkhead did not go all the way to the deck so it could and did overflow the top of the bulkhead

[@user-ov9ob7zz4t]

Hi! The problem You mention in this epsode is more serious than many people think. Not so far away from You (Gibraltar Strait) and not so long ago (31 October 2023) another sailboat has been lost the way You've described. Polish yacht s/v Grazie Mamma was attacked by killer whales (a common issue on these waters) and lost its rudder. The event lasted roughly 45 minutes. Subsequently the boat with severe leak was being towed by rescuers to the port of Tanger, but flooding was too severe to save it. The boat was probably of Benetteau design with spade rudder. I personally didn't saw it, but I was onboard two other boats (Bavaria-s 38) owned by the same cruise company. Also a spade rudder and (as far as I know) no aft bulkhead. They could be in the same jeopardy after a similar event. Fortunately, they operate on Baltic Sea and Norwegian Coast, not Mediterranean and Canary Islands. Regards, -J. PS. BTW: Those 2 cruises i Was on is so far my only experience with blue water sailing, another one is already planned. And this is all Your fault - I decided to return to sailing after many decades encouraged by watching Your channel. Simply once KZbin displayed me an episode from Svalbard, when you visited Pyramiden. I was there just a year before, fresh memories and so on... So I fell into this rabbit hole -truly, deeply, madly :) :) :) I binge watched all the current episodes and archival ones from the very begining. Joining two parts of the story took me couple of months, when You reached Scotland. Simultanously I decided for my first blue water sailing voyage...

[@danaburchatz1774]

You kids answered so many of my questions on how to do projects, at least start them, so much great advice and I know information! Been a long time fan!

[@DBX277]

My oh my- thanks for a great lesson on “sinking” risk related to lack of water tight areas… no idea as to the risks and potential risk management options! What a marvelous learning opportunity for so many viewers!!! Thanks again

[@brendariley8982]

Guys, I understood all of this. Thank you for explaining this so well. I'm very fond of triple back up systems.

[@therealmattcarr]

I love watching boat refits. Can't wait to tackle one of my own. Keep up the awesome work.

[@ShadyTreeBoatCo]

Excellent video. The rudder design you were thinking of was transom hung. Like all design these also have issues. The biggest benefit to a skeg wither full skeg or half(Like your boat) is the protection provide by the skeg. Transom hung can have the transom removed from the boat on a object strike if the transom build quality is substandard. I am building my own 40ft sail boat. And I probably going with a fin rudder. As for watertight bulkheads you have to remember the Titanic for this one. If the water tight bulked has openings and the water level ever exceeds the height of the nearest opening(In the case of an opening for chain locker or pilot berth cut out) It serves no purpose. You also have to remember that water weighs alot and this will drastically change the balance of the boat. The saving grace is the bow and stern of a sailboat tend to be above or at the DWL which reduces the amount water that can enter to begin with. For ships there is a design parameter stating how many watertight spaces can be flooded before critical failure as the water tight bulkheads usually stop above the flooded water line. For ships it is 2 compartments. I am not sure if the ABYC has one. Also be wary of over designing your boat. You know have three bilge pumps that need 100% uptime to take care of. My boat will have 1 bilge pocket, 1 main bilge pump, an emergency backup bilge pump, a manual hand pump and an emergency crash pump. This should be the minimum required for any blue water boats. All my bulkheads will be filleted to the hull with small 10mmx10mm openings for drainage to the bilge pocket. P.S Catamarans don't sink. When yachts are made out of fiberglass or wood they are positively buoyant to begin with. The down side to a mono hull is the very heavy weight permanently affixed to the bottom which makes it sink

[@jnbond]

I really appreciated this video and Dan's teaching! I found it fascinating!

[@danagovang2520]

Our Kiskadee was a 1980 Hughes 38. The only collision bulkhead was between the anchor locker and V-berth. She had a skeg hung rudder.

[@gtbdds]

This was a wonderful explanation bulkhead science. You two have seemingly really considered all the details in this rebuild. Congrats! Can't wait to see the finished project

[@johnperry7534]

Thanks interesting. My boat was a Seawind 1160 cat and the rudder hit something hard and bent the stock , there was a bulkhead which was watertight but the actual rudder hole in the hull had a built in fibreglass pipe section which the stock is inserted into and its top is above the water line in fibreglass was so strongly built nothing happened to it . Took huge force to do this and the rudder when bent jammed against the hull and I had to cut some off it to free it next to the hull . But no water at all came in and if It did there is a screw in bulkhead which would slow down enough water anyway. All you’re saying is quite right . Great work . Amazing how strong the fibreglass is on those seawinds. Good work, I think those sail drives are rarely torn off they’re very strong , you’re both great sailors always good work

[@bunkie2100]

Aircraft control surfaces (rudders and ailerons) are, often, balanced in the same way with pivot back from the leading edge to provide aerodynamic pressure to assist in deflection.

[@EggchaserNZ]

absolutely loved the learning opportunity! knowledge transfer from boating redesign to sailing is always top knotch from you two!

[@noasailing27feet]

Thats why i went back to long keeled sailboat. Love the behavior in rough seas as well .

[@eleanordeckert3309]

Just look at how all of that architectural education is getting put to work! Yaaaay for you two! What a team!!!!

[@janicearmstrong9645]

I agree .A great explanation of good bulkhead planning. Kudos on your renovation so far.

[@sergiyisakov5192]

You guys will soon establish your own boat factory

[@creageous]

That was a very informative episode. I learned a lot.

[@Julia_Berrrlin]

love when you explain stuff

[@kaahua]

Hello to you I've been following you since the beginning and really appreciate your journey. On the architectural point, I agree 100% with the analysis of creating watertight partitions. This is what I designed, drawn and applied to "Kaahua", I even pushed the concept very far since with structural stations every 60 cm approximately. I literally created watertight boxes between the bottom of the hull and the funds of cofferdams. Then each cofferdams under the floor rises 30 cm above the waterline. Not to mention that the ends are waterproof over the entire height and constitute a reserve of buoyancy greater than the weight of the hull. If the hull were to be punctured, a single cofferdam would fill with 150 liters of water up to the flotation level , that is to say 30 cm below the floor. And if I have an opening lower down (under the cofferdam floor), it is even much less and only half the width because in this part it is also partitioned longitudinally.

[@giacomomurari]

Every sailor wants a new boat "one meter longer". You did your boat "one metere longer" IN THE INSIDE! It's pure genius :) Buon Vento

[@WM_Partners]

You explained your process and the need exceptionally well. Thank you for demonstrating the “flaw” in most production boats and the obvious need for water tight bulkheads. That’s the reason the Titanic sank.

[@zaneelliot6963]

I have learned a lot about sail boats, thanks to the University of Uma ship engineering. LOL

[@Iseevideo101]

I can hardly wait to see the finished boat.

[@davidbrayshaw3529]

I am glad that you have brought to everyone's attention just how rudder design has the potential to sink a vessel. Time and time again the same old tired argument of keel design gets rehashed with absolutely no mention of rudder design. And of course, in your discussion you note very clearly the value of a bulkhead forward of the rudder stock. A friend of mine was crewing on a Farr 52 skippered by the late Graeme Ainley in a Sydney to Hobart race, a number of years ago. The rudder was impacted by what the crew believed to be a sunfish or a whale. This caused the bottom bearing of the rudder stock to fracture. Without the bearing in place, the rudder stock thrashed a sizeable hole in the underside of the vessel. Within only a minute or two, the water ingress became unmanageable, and the order was given to man the life raft and a mayday call was made. There was no watertight bulkhead built into that particular vessel. Fortunately, no lives were lost nor injuries incurred during the incident and the crew effectively disembarked their vessel and immediately climbed aboard a fellow competitor's yacht. I remember seeing the skipper and co-owner of the yacht interviewed on television, following the race. His statement to the reporter was something along the lines of: "It's a very sobering experience watching your vessel sink below the ocean's surface from a boat that your meant to be racing against". Graeme and his crew had the good fortune of having such a failure occur in a fleet of maybe 60 or 70 yachts and in favourable conditions. Think about this from a cruiser's perspective. That outcome could have been very different.

[@stephenprouty8728]

... excellent rant ... a lot of great info included with it ... I don't sail now due to leg loss, but would definitely want to apply your ideas of compartmentalising to my boat ...

[@WhyWorry1]

Thank you for this video! I’ve been trying to picture how an orca > broken rudder > sunken boat. You explained it so well. That’s insane that a bulkhead in front of the rudder is not standard.

[@benshore7357]

Good times 🎉 I have a couple of old marine shop manuals. They were from the us navy. Large hard bound books with many pictures and explanations of repairs. They have several chapters on what to do when sinking. The larger ships have stocks of plywood and other lumber. Use these to patch hull while under way. Lots of useful information

[@garymost6255]

Fantastic description and detailed explanation of the rudder and bulkhead design systems and (possible) issues. The planning and forethought you both are putting into this project is simply amazing. Thanks for sharing and informing!!

[@beakyturbot]

In making such considered modifications, also employing your experiences with other boats, including racing yachts, I think Uma will feel very different when you get her back on the water. I'm very excited.

[@robertlaird6746]

My future boat will be a Cyber 48 and it has some water tight bulkheads in each hull. That was an eye opener how you explained all of this even though I've seen that video of the boat sinking several times. I didn't even think about how it sunk. This makes me look at things a lot closer. Thanks for sharing!

[@davidschwab6774]

Just took my freshly converted electric sailboat out for its first motor trial. Y'all have been a great inspiration for me. Thanks!

[@SailingUma]

Awesome!!! What system are you using? How’d the sea trial go?

[@davidschwab6774]

@@SailingUma I'm using a motor kit from Electric Yacht, and a bank of Dakota 48V lithium ion batteries. So far just did a little circle around the harbour and that went fine. The funniest thing is that I'm noticing that my rudder is vibrating like crazy. I guess I never noticed before since the diesel was so loud. I thought I had messed up the prop shaft alignment or something, but if the rudder is held a little to one side like at the dock tests, the noise isn't present. By the way, I've been thinking about joining your patreon for a long time now. I think it's time to pull the trigger finally lol.

[@hauke3644]

I’ve been sailing a Salona 40 with a damaged rudder seal. The boat had a separate rudder compartment-but the previous owner had opened that for a heat pipe and not done any sealing… Luckily this happened before leaving the coast and some hundred liters of water from one day could be pumped out. I am surprised that a highly priced boat like Arcona lacks such an essential part!

[@allenwinston5157]

Love the Education moment! That was awesome and so good to know the difference. Thank you for taking the time to share.

[@brucewoodford6349]

Excellent explanation! I appreciate you sharing your knowledge.

[@somebody1869]

My 1978 Beneteau First 30 doesn’t have a watertight bulkhead. But it does have an almost full skeg.

[@erikbarkefors2441]

The Arcona that sank had a large diameter rudder stock at the hull bearing. Then it was conically turned a bit and a smaller diameter up at the rudder quadrant. The break occurred at the transition between the conical turning and the upper part of the rudder stock.

[@danmerillat]

Good rant. Great explanation of rudder types and why you'd want to isolate your rudder.

[@Gottenhimfella]

11:30 The proper term for rudders hung "off the back of the boat" is transom hung. These can be designed with a kick up blade, or a dagger blade, which makes them very suitable for shallow water or for getting them up out of the zone of interest for curious or playful orca. They also can easily be designed to never compromise the watertight integrity of the hull.

[@balaenopteramusculus]

Loved this episode. Nice and clear deep-dive into your design choices for an optimal blue water boat.

[@Ron-jf1xz]

Besides various bungs, I always carried two gallons of Bondo. Very few people know that Bondo will set up under water. I heard of a guy who got holed and mixed up a batch of bondo, gooped it all over his glove and shoved it into the hole. When the bondo set up, he pulled his hand out of the glove, pumped the bilge dry, and sailed home.

[@rebelwolves]

There are production boats with water-right bulkheads. The ones I know of are expensive boats though. I can't remember which of the Hallberg Rassy boats have them, but I know several do. Krakens have 2 water right bulkheads up front, and one in the back. Plus the Kraken uses an encapsulated keel and skeg hung rudder. Not only is the rudder sked hung but even if you loose the rudder the design is fully above the water line so no water comes in (you can also service or replace every bearing on the rudder without a haul out)

[@robertfontaine3650]

Love the Krakens but will never be able to afford one.

[@bf5549]

Probably a little late to draw attention to it but having followed last years single hand Golen Globe race, I found the modifications made for companionways quite fascinating. Their website had boat tours and tech details for all the entrants. Boats were all similar vintage to Uma. And watertight bulkheads were an entry requirement. For our 42 ft. Alpa centre cockpit ketch my husband did a clever quick fix for the 2 companionways. Using one inch thick plank that fit the groove, he had three L grooved segments cut horizontally to replace the one piece slider. Much easier to store and very strong. We often left the top one or two out for circulation but were still well protected from the weather. Sorry to "run on" but your video was so great, it gets a person thinking of what works and what doesn't. You look like you are well on your way to "what works". She'll be a great boat to sail.

[@halolynx0114]

I love this sailing rant we need more

[@Conan3145]

17:35 One bilge pump to rule all the through holes. Nice.

[@seanmolony-redstickastro238]

This is a 60 inch flat screen watching event rather than the iPad!

[@user-cd2cy5cg6n]

I have an '85 Gulfstar masthead sloop. Does not have a watertight bulkhead fore of the rudder post. But after watching this video, I will add one. Great idea!

[@bootsandsocks]

This is a big thing that I have often wondered about. It seams like almost all sailboats do not have water tight bulkheads. I have a 2001 S&S and the only water tight areas I have are the anchor locker and the lazarette, but my rudder comes up under my bed in the back cabin. But the big thing I got is a big skeg with a 3 inch stainless tube for my rudder