While working for an off shore geophysical research company got to check out a crushed data canister from a streamer that had been recovered after breaking free from the towing ship. The streamer was made up of alternating hydrophones and canisters that would process the sonic data and send it back to the ship. At the end of the streamer was a buoy. The buoy keep the far end of the streamer afloat but the end closest to the ship sank straight down before it could be recovered. I am not sure how long the part of the steamer was that broke off. The canisters were a titanium cylinder about two feet long and five inches in diameter with a connector at each end to connect to the steamer cable. They were filled with a sandwich of PC boards and shock absorbing foam. The ends were welded on titanium plates with the streamer connectors embedded in them inside of a threaded ring that attached to the streamer cable.
The canisters that went the deepest looked like crushed beer cans in the middle. After sawing through them to get a across section view, the foam, PC boards and all the components on them were just squashed into a solid mass between the folds of the crushed canister. Was very impressive. I wish I had a photo to show but only can find this of a typical streamer setup.
