Why Don’t SailGP Boats Use Spinnakers?!?!?

[@eurotrash4629]

I'd love to understand why Jibs are sometimes flown with Spinnakers and other times not. Again great clear & brief presentation. Thanks!

[@SailingTipsCa]

I love your idea - Top 5 Reasons to Fly a Jib and Spinnaker Together!!! And I already have all the footage I need! Thanks for the suggestion - keep 'em coming!!!

[@SailingTipsCa]

Okay here it is: Five Reasons to Fly a Spinnaker and Jib Together kzbin.info/www/bejne/lXnNfayrpbuFfcU

[@chadrew6]

Depends on the angle of the wind. On a reach or a very close broad reach, the jib can be useful in filling in the gap between the mainsail and the spinnaker but going dead down wind or on a very broad reach, they’re not so useful because they’re usually hidden behind the mainsail

[@Seafariireland]

Super lesson, thank you. SkipRay, Kerry, Ireland.

[@SailingTipsCa]

Thanks - glad you liked it!

[@tomfortner3023]

That answers a few questions I've had. Thanks for sharing.

[@SailingTipsCa]

Glad you found it helpful - thanks for watching!

[@robertlee8042]

Really excellent. Just fact after fact, in order, perfectly laid out. Each with an inference.

[@SailingTipsCa]

Thanks - glad you liked it!!!

[@LoanwordEggcorn]

Thanks for another really clear explanation. Foiling racing boats probably could try to deploy a spinnaker, but it would be backwinded, collapsed and acting is a massive air brake if they did. Which is why they (and their designers) don't have them. Didn't know the F-82R had that much apparent wind effect. 90 degrees of apparent wind change is very impressive. All the more reason to get a (performance) trimaran.

[@SailingTipsCa]

Interestingly all the fast multihulls around here still carry spinnakers but none of them are full-foiling. For example our F-82R can "only" sail at 1.2 times the wind speed, which is much less than a full-foiler that can sail at 2-3 times the wind speed. Spinnakers do allow us to sail very deep downwind, but depending on how the wind angle compares to the race course we do often find ourselves switching back to whites (e.g. jib or screacher) while the monohulls are still flying spinnakers.

[@LoanwordEggcorn]

@@SailingTipsCa Got it. Seems like it depends whether it's windy enough to have enough apparent wind effect. Sailing at or near wind speed is great, and foiling is very hard to maintain, and full flying (foiling all hulls out of the water) even more so. Was very impressed with the fully flying single handed large trimaran in your other video. Gitana. Does that mean its autopilot sails to true wind direction? I.e., it keeps the stingray main hull lifting foil flying by sailing to a particular angle to the apparent wind.

[@SailingTipsCa]

@@LoanwordEggcorn Lots of “normal” fast boats set their autopilot to follow the apparent wind, in part because that’s what the sails are set for, and in part because it’s very easy to measure that with instruments without complex calculations. Then the boat will head down in gusts and up in lulls, but the apparent wind stays the same. I’m not 100% sure what Gitana does in this case but they may use a combination of measurements, including apparent wind, boat speed, and ride height. Their autopilot is FAR more complex than a “normal” autopilot!!!

[@LoanwordEggcorn]

@@SailingTipsCa Thanks, I meant apparent wind of course. Typoed true wind, corrected. And agree it could be just one of many inputs, but probably one of the main ones. Some sort of averaged wave height would also be a reasonable input, where the smoothing function is non-trivial. And of course in big enough sea states, full flyers can't fly, just like any motor powered hydrofoil..

[@SailingTipsCa]

@@LoanwordEggcorn They certainly are limited by wave height. I expect boat speed is also a big part of the equation because that impacts the lift provided by the foils, so they would want to keep that constant. I bet the autopilot heads down once the boat gets going too fast and heads up when it slows down.

[@WillN2Go1]

Good video. Brief and to the point. As a rookie sailor I was watching the recent America's Cup in Aukland (I was on the net) and had the thought: Okay, what point of sail? It was all close hauled. Boats heading straight at each other - close hauled! How is that possible? Then I drew the vectors - guessing True Wind was 20 knots boat speeds 45 knots - and there it was - all close hauled. Apparent wind was completely different. While out solo sailing I noticed this as well. Downwind turned out to be the most difficult point of sail for me on 28' -36' monohulls. Mostly I seemed to be close hauled or close reached. Beam reach seemed harder to trim for. (You might want to make a video on actual tacking. Almost all the diagrams I've seen in the books show a boat tacking 90°, no accounting for Apparent Wind. One day another rookie and I were out and needed to tack to get back to the marina. We tacked 90° - nope, keep turning.... We must have been 120° before we got wind; we were heading (slightly) backwards. )

[@SailingTipsCa]

Thanks for the suggestion on doing a tacking video! Currents will also have a huge effect on your tacking angles, so you might have been in some current? Some boats also don’t have the jib/genoa cars in the right place, which will also have a huge effect on tacking angle. Have you checked out the genoa car video? kzbin.info/www/bejne/aZjPhH-nlMqLjqc. The sheeting angle should also be around 10 degrees off centreline for a sporty cruiser, 7-8 degrees for a racer.

[@LoanwordEggcorn]

If you're using a traveller, remember to adjust it before or after the tack. Having it too low after the tack (due to being high on the previous tack) can take enough power from the mainsail to maybe stall the tack. So generically, sail trim probably. Also jib trim, as @Sailing Tips noted above, along with current. Have not studied the physics, but I assume a jib does more during a tack to pull the bow across the wind than the mainsail. So jib trim, including twist, could make more difference than the main.

[@WayOfHaQodesh]

Amazing content, thank you so much for all your informative videos.

[@SailingTipsCa]

Glad you like them!

[@chadrew6]

Because their speed is so fast that the apparent wind is always forward of the beam preventing use of a spinnaker

[@SailingTipsCa]

Exactly! Even on my “slow” F-82R the apparent wind is almost always forward of the beam and we typically fly a spinnaker at 70-90 degrees apparent. But on a SailGP boat the difference in apparent wind between upwind and downwind is only ~15 degrees which is too far forward for a spinnaker.

[@glenpang5025]

does that mean these super fast boats can't go up wind? At 3x speed of the wind while pointing 90 degrees to the true wind direction, as soon as the boat points 85 degrees, the sails will begin to luff and depower.

[@SailingTipsCa]

Yes they can sail upwind, typically tacking and gybing through around 90 degrees, however to do this they have much tighter sheeting angles than "normal" boats. For example when a "normal" boat tacks through 90 degrees the true wind will be at 45 degrees and the apparent wind at around 30 degrees. On these boats the apparent wind will be far further forward, so they need much flatter sails, and the rigid wing main is a big part of being able to sail with the apparent wind so far forward because it doesn't luff like a fabric sail. And when they are sailing "downwind" the apparent wind will only be a few degrees aft of the upwind position, so only a very slight ease of the sheets required. Hope this helps!

[@glenpang5025]

hmm, let's say the ultra fast sailboat is fully pinched and pointing 45 degrees or higher into true wind direction. Razor blade jib & main sail trimmed to the max, how much faster than ambient wind speed can the boat move? certainly not 3x wind speed? Maybe 1.2% of wind speed? (for sure 3x wind speed when broad reaching) The only higher performance sailboat I have sailed is a Hobie cat and it's easy to mentally conceptualize such a thin hull cutting through water because of so little resistance through water. I.E. pulling a dinghy through water vs a kayak, you can feel the difference. Apparent wind and these levels of efficiency is blowing my mind!

[@SailingTipsCa]

@@glenpang5025 Here’s a link to a wind speed vs boat speed graph that shows the SailGP boats can remarkably go 3x wind speed but unfortunately it doesn’t include the point of sail: www.catsailingnews.com/2019/02/sail-gp-f50s-boat-speed-vs-true-wind.html I think they can still go 2+ times wind speed tacking upwind at 90 degrees. Just watch the last SailGP in Denmark where the wind was 8-10 knots and I’m pretty sure they were going more than twice that upwind! Remarkable!!!

[@_srgg_]

I’ve sailed on a monohull foiling boat that had spinnaker, called the 69F, you should definitely check it out. I started to fly at 10-12 knots of boat speed with 6-8 knots of wind

[@SailingTipsCa]

Looks like a very cool boat! Those spinnakers are also very flat and also essentially working as upwind sails!

[@_srgg_]

@@SailingTipsCayes, when there’s not enough wind to foil, some teams used the spinnaker for upwind

[@SailingTipsCa]

@@_srgg_ What I meant was that the boat is so fast that the apparent wind is probably far forward of the beam even when you’re sailing downwind i.e. you’re always sailing upwind.

[@_srgg_]

@@SailingTipsCait can be true

[@SailingTipsCa]

@@_srgg_ My F-82R trimaran doesn’t have lifting foils and even on that we’re pretty much always sailing with the apparent wind forward of the beam, even under spinnaker!

[@jaspergatrill3461]

Excellent logical videos! 👍

[@SailingTipsCa]

Thanks - glad you liked it!

[@chadrew6]

Because at those speeds, which often exceed the actual wind, speed, the apparent wind is too far forward of the beam to make a spinnaker useful.

[@SailingTipsCa]

Exactly!!!!

[@InYourDreams-Andia]

Well explained!

[@SailingTipsCa]

Thanks - glad you liked it!

[@marcantoineroussel]

Really well explained! I'm now curious on what sails you actually use on your trimaran (and how often).

[@SailingTipsCa]

Thanks! We have three headsails for our trimaran - blade jib (laying on deck at 0:37 and 1:47 in video), screacher (bowsprint-mounted furling genoa at 1:47 video), and a spinnaker (0:37 in the video). You can see the spinnaker tack at 1:47 just forward of the screacher furler on the bowsprit. In really light wind (0-3 knots) we typically use the screacher on all points of sail, because we will be beating or close reaching in the apparent wind regardless of the true wind. In 4-5 knots we still use the screacher for beating, but switch to the spinnaker for reaching and running. Our spinnaker is very flat and typically flies at 60-90 degrees apparent even when running. In 6-12 knots we switch to the blade jib for beating, but still use the screacher for reaching and the spinnaker for running. In all cases the apparent wind is still forward of the beam. In 12 knots of true wind we will see up to 15 knots of boat speed under spinnaker, which will bend the true wind at 150 degrees forward to about 60 degrees apparent. Because the apparent wind is so far forward, in 12+ knots we can really only fly the spinnaker at 150-160 degrees true, so if our course is above that (e.g. 140 degrees true or less) we have to fly the screacher because the apparent wind will be so far forward. In 13-20 knots we use the blade jib for beating and reaching, and start using the screacher more for running, unless we’re going really deep downwind and have lots of sea room, in which case we may still use the spinnaker up to around 20 knots, but only if there is sea room to bear away and depower. At 20+ knots it’s mostly blade jib and main sail, and we’ll start reefing the main sail at this point as well. We may still use the screacher for running with a reefed main sail if we’re going really deep downwind and have lots of sea room to depower. There’s lots of great info on Farrier-designed trimarans at chesapeakemultihulls.org/wp-content/uploads/2019/07/2012_Sailing_Manual.pdf

[@marcantoineroussel]

​@@SailingTipsCa I'm a little blown away by the amount of details and care in the answer. Thanks a lot for the in depth answer!

[@SailingTipsCa]

@@marcantoineroussel Glad it was helpful! Hopefully also a useful reference for owners and crew of similar boats!

[@davidrumbelow]

Love your work, you might want to do an article as to why a Finn ( for example can sail closer to the wind than a scow. I am a former Finn , Fling Dutchman and Lazer owner/ sailor

[@SailingTipsCa]

Thanks! Great idea!!!

[@WayOfHaQodesh]

Questions: Would this only apply to foiling trimarans, as I heard you mention that? Or is it more dependent on what speed your trimaran is reaching?

[@SailingTipsCa]

Lots of fast non-foiling trimarans also generally don’t use spinnakers either, because the speed of the boat drives the apparent wind forward so much that they are almost always sailing upwind. Even on my F-82R trimaran it’s very rare that the apparent wind is aft of the beam, so we use a very flat spinnaker that flies well in 60-90 degrees apparent.

[@WayOfHaQodesh]

@@SailingTipsCa Thank you kindly!

[@robertcain3426]

Is this why AC foiling boats cannot point any higher than 45° as shown on tv graphics overlaid on the course? Is it, the faster you go the more you have to bear away because the wind is being bent to come where the boat is pointing? Cheers😊

[@SailingTipsCa]

To me they appear to tack and gybe through about 90 degrees so 45 degrees off the wind as you say. But in order to do this they need incredibly tight sheeting angles for upwind and only ease the sheets slightly for downwind.

[@robertcain3426]

@@SailingTipsCa So, do you agree that the faster you go, the less you can make to true wind. Debating this subject, I believe that thos is one of the biggest reasons slower boats seem to point higher to true wind, all things being equal. Cheers

[@SailingTipsCa]

@@robertcain3426 Yes the faster they go the further they drive the apparent wind forward, which ultimately limits how high they can point. At the same time pointing as high as possible in a fast boat generally doesn’t yield the best VMG, or quickest time to the windward mark. In my trimaran I can point as high as any monohull but then I’m also stuck going about the same speed as them. Or I can bear away 5 degrees and go twice as fast, and still beat them to the windward mark even though I’m not pointing as high because the extra speed more than compensates.

[@kenjackson5685]

1st class

[@SailingTipsCa]

Thanks - glad you liked it!

[@Frank-E]

Thanks. Could you possibly do one with a cruising chute on a pro-furl spinex?

[@SailingTipsCa]

Good idea! What specific aspects are you interested in?

[@Frank-E]

@@SailingTipsCa I bought a used boat that came with a pro-furl Spinex with a cruising chute in a bag. My previous boat just had a genoa and a main. There was also a spinnaker but we never used it. We are a family and strictly cruisers. Would be nice to get ideas on wind angles, wind speed (for when to use it and not), butterfly with a Genoa and a cruising chute? Dead down wind or gybe? Ocean passages and maybe single handed? Thought I ask since you explain things in an easy and straightforward manner. Thank you.

[@SailingTipsCa]

I’ll do a video when I can get some footage. In the meantime a cruising chute on a furler sounds perfect for your situation! They are cut fairly flat with small shoulders so quite forgiving compared to larger/fuller racing kites. It should fly nicely in about 80-150 degrees apparent. Basically hoist the snake, head off on a broad reach, and unfurl like a furling genoa. To gybe you can either furl, gybe the main, and unfurl on the other gybe, or use the technique in this video: kzbin.info/www/bejne/hGSlipucjruZqJo I’d start in lighter wind, say under 5 knots until you get used to how it works, then move up to 10, 15 etc. Definitely gybe rather than wing-on-wing, because the boat is much more stable and also faster when reaching than dead downwind.

[@Frank-E]

@@SailingTipsCa Thank you! What wind speed would you say would be the maximum, about 20-25 knots? Let’s say we are on a passage or maybe just a couple of days and night sails and we have used the chute but wind angle and or wind speed picks up, would you keep it mounted and ready (furled in obviously) when sailing just the genoa and main or would you tuck it away and mount it again when conditions seem more favorable?

[@SailingTipsCa]

Good questions! If it’s a 1.5oz kite and you have a boat around 40 feet the kite should be fine in 20-25 knots of true breeze. But if it’s lighter (e.g. 0.75oz) then 20-25 knots would be at the top end or slightly above and you’re starting to risk damaging the kite. But 1.5oz kites are pretty robust and you’re likely to have trouble controlling the boat or breaking other things before you threaten the kite. If the wind picks up or moves forward I might keep it raised but furled if I’m likely to use it in the next 15 minutes or so, otherwise I’d likely take it down. Depending on the layout of your boat you could potentially leave it all connected and stuff it down a hatch, or lashed to the deck somewhere. We have a roller furling screacher (kind of like a Code 0) on our trimaran that we leave connected with the snake lashed to the nets when we’re not using it. I think you can see it in parts of our spinnaker raising video kzbin.info/www/bejne/iZCtnJWsfLF6brM.

[@The442nd]

Jedi SailAlot

[@SailingTipsCa]

Does that mean that the true nature of my father needs to remain a mystery?

[@The442nd]

@@SailingTipsCa The Force is strong with you. That's easy to see

[@NewZealandPakeha]

Can this be a 100f cruiser.

[@SailingTipsCa]

Maybe but you’d have to pack light to keep foiling!