Buoyancy Foam >488m

Hello. We’ll be testing out our deep sea remote underwater video system this weekend but are still curious to make it a drop camera setup in order to take away the drag that comes with a tethered setup. Just wanted to ask if there is a way to get the buoyancy foam still buoyant enough at depth in order to bring the camera back up after the burnwire has released the weight (using more foam mayhaps…?). I read that the buoyancy foam can go down to 488m when coated but we’ll want to probably go deeper than that. Would it still provide some form of buoyancy if it goes deeper and gets waterlogged or will it lose all buoyancy if it goes deeper than the tested depth? Cheers!

Hi @Tides,

I asked about this internally and was told once it gets over-pressurised it starts to undergo plastic deformation and gradually loses its buoyancy, but we don’t have detailed measurements of the rate, so we can’t meaningfully suggest a specific volume of foam or coating method that would be sufficient for your purposes - you would need to test, especially given the application is un-tethered and has a potentially unknown depth, in which case the equipment may be lost if the buoyancy fails.

You could also potentially use a larger enclosure, or an extra one, although that may be prohibitively expensive if you’re not also able to make use of the additional space in some way.

@Tides Have you seen this post?

Something like this foam might be worth considering since it’s made for the depths that you want.
https://esyntactic.com/products-solutions/syntactic-buoyancy-materials/microsphere-syntactic-foam/