Hide and Seek during the Battle of the Atlantic with

[@paulfennell01]

It hasn’t even aired yet and I already gave it a thumbs up, Im that confident in Ryan and his crew!

[@VantageMain]

Imagine giving it a thumbs up😅

[@BaronFeydRautha]

Should have waited to see those ten minutes of dead frames.

[@brianb8060]

I found out about thermoclines in my early teens, from playing Silent Service 2, on PC in the early 90s.

[@GaryMCurran]

Today, much of our antisubmarine warfare is carried out by submarines, which means they can easily get on either side of the thermocline. But, both submarines and surface ships now carry 'towed array sonar', which allows them to tow an array of passive sonar receptors behind the ship or submarine. There are no transmitters (to my knowledge) on these towed arrays, so they are completely passive, they just listen. But, from the surface ship they can be deployed below a thermocline. Remember that he said that sound from under the layer would not penetrate upwards. This also works, in some cases, for the surface ship, in that a strong thermocline makes it difficult for the submarine to hear an approaching surface ship, although lower frequency sounds will more easily penetrate a layer. The submarine with a good sonar array always has the advantage, but thermoclines, especially in the day of nuclear powered submarines, have always played a good part in the hide and seek of anti-submarine warfare. One other thing that I should note. In a sub versus sub scenario, it's actually possible to 'float' the towed array above the layer, so you can listen above the layer while you 'hide' underneath of it, making it harder for your opponent to find you.

[@spaceghostohio7989]

Was on a Knox class back in the day. Had a AN/SQR - 18A towed array on board. No transmitters. Every couple of hours dropped a BT ( Bathythermograph ) to check out water conditions and see where the thermal layer was.

[@n6mz]

Sailing in Puget Sound in summer, where the depth sounder should have read 600+ feet, I routinely saw readings of just a few feet, thanks to thermoclines. There was major helmsman puckering the first few times it happened before I realized what it was.

[@ryder6070]

This is interesting. I sail in Alaska, the same thing is usually attributed to whales. I have been able to confirm this many times. Grey whales, dolphin super pods, etc. However, thermoclines must explain some of these happenings. One last thing, many transducers max depth is ~500-600 feet. Deeper than that may produce false readings. Thanks for your comment, this is very interesting

[@n6mz]

@@ryder6070 I think my instrument's max is 600ft but I never get soundings that deep (if the bottom is flat and hard I think I've seen 200ft). I should have said that I was in water over 600ft deep per the electronic chart.

[@wfoj21]

Cool. Two museum Curators doing a two part presentation - being done on a third different Ship (or should I say vessel to make Paul happier) then their own (I watched Part 2 first- did not have that "click" to me until seeing Part 1. Pt 2 available before 1 is a slight mixup I hope gets corrected next time.

[@ryder6070]

Started watching Cod's channel. It's great

[@thekidfromcleveland3944]

Hey Paul🖐 Im disappointed to see barge 225 go too. Hopefully we'll get a nice enthusiastic neighbor like New Jersey

[@Michael_Brock]

Editing error, last 60% is black space.

[@kolt4d559]

Yep.

[@shubinternet]

Starting at the @4:47 mark. From there on, it's just plain black.

[@guaposneeze]

It's a digital simulation of how much information passes through the Thermocline layers when you dive. Ryan is actually fully nude in that part of the video, but you can't tell because of the temperature gradient reflecting it all back to him.

[@roderickcampbell2105]

@@guaposneeze That is brilliant. Never know what you'll see in the comments. This conjures up many interesting thoughts/ideas. None of them printable as no thermoclines exist to protect the innocent.

[@terryrogers6232]

"Did the Germans know about it?" ... I was told one time, that several U Boats penetrated the St. Lawrence River where a convoy was assembling. One captain fired torpedoes near the surface, moved a bit and went down to the bottom and just sat there hiding beneath a thermocline. Another was forced to hide the same way because of damage. Their actions seem to indicate that at least some of the U Boat captains knew of thermoclines in the river and bay. See Wikipedia, "Battle of the St. Lawrence." My uncle was a seaman on one of the US DEs in one of the continuing St. Lawrence Battles. When he told his family of where he was battling U Boats, they refused to believe him.

[@bartk07]

From my informal searches, Germans didn't know about thermocline, even Royal Navy seems not to know about thermocline. I read about a crew of catalina who dropped sonobuoys, destroyed one u-boat and still heard propeller noise. That was another undetected u-boat whose sounds propagated through deep see sound duct. In the case you describe, I think they could have though they could fool asdic just by hiding at the bottom and later the teory was attached to it.

[@tomtrenter3208]

@@bartk07 Germans were aware of water temp profiles but were unable to exploit it due to their inability to plot it often enough.

[@tomhenry897]

Read about this long ago Lot of depth chargers on water and whales

[@tomtrenter3208]

I think it's highly probable that the germans knew about water temps. I don't know for certain when the winch BT cast was first developed and deployed. They were heavily used during the cold war until they were replaced by the XBT (eXpendable BathyThermograph) in the late 60's/ early 70's. The old BT's were hated by the sonar techs who had to do the casts because they were exposed to bad weather because the info they gathered was very useful. There were several cases of guys getting swept overboard and equipment being destroyed. The value of water temps is that it's the biggest factor in the speed of sound in water, salinity and pressure also play a part but temp is the biggest determining factor. Determining the actual ray path of sound through seawater is a complex equation (snell's law is one) that needs up to date info to calculate layer depth and several other pieces of the puzzle to predict detection ranges.

[@esmith3329]

Ryan, could you do a video or a series of videos about the ASW fight off the US East Coast during WWII. There is a great book Torpedo Junction, about USCG RADM James Alger (then LT) and his fight in WWII. He's a relative of mine but his story is important.

[@JoshuaTootell]

I read that book a long time ago.

[@burroaks7]

very cool

[@spaceghostohio7989]

The original sonobuoy.

[@ronaldmiller2740]

HI RYAN AND PAUL ,, GREAT VIDEO!! MY SON MAX LIKES SUBS ,,SO INTERESTING..LOST PART OF THE VIDEO..THANKS..

[@steveweinberg462]

Dazzle paint scheme? I didn't realize they were still using it in late WWII.

[@bigsarge2085]

✌️✌️

[@robertkoons1154]

Its Awl-ban-ee not Al (as in Albania or Al Bundy) or however they say the name of the same spelled town in Georgia. If you need to see how a town is pronounced turn your car radio on when you are in the area.

[@merlinwizard1000]

25th, 26 September 2023

[@Consequator]

Thats a lot of black screen.