# Uncoated or coated LAST-A-FOAM **URL:** \ **Category:** Buoyancy and Ballast\ **Created:** [November 4, 2016, 3:08am UTC](https://discuss.bluerobotics.com/t/uncoated-or-coated-last-a-foam/540 "2016-11-04T03:08:14Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![rjehangir](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/rjehangir/32/671_2.png) [@rjehangir](https://discuss.bluerobotics.com/u/rjehangir)\ **Post date:** [November 4, 2016, 5:04am UTC](https://discuss.bluerobotics.com/t/uncoated-or-coated-last-a-foam/540/2 "2016-11-04T05:04:50Z")
Hi Vincenzo, The foam is urethane foam, and while it is closed cell foam, at high pressures water can be absorbed into the foam, which would change buoyancy. Therefore, adding a waterproof coating to the foam prevent water from entering into the foam cells increases the depth rating. The coating does not have to be very hard or structurally strong. There are many coatings that can work as long as they provide a waterproof layer. At the simplest, I would recommend a waterproof paint such as latex or epoxy based paint. I hope that helps! -Rusty --- _[View the full topic](https://discuss.bluerobotics.com/t/uncoated-or-coated-last-a-foam/540)._