Floating Mat material or recomendations

I'm looking for a the type of material that is used to make floating mats (similar to yoga mats). Hoping to find this in liquid form to mould myself rather than buy to cut.

The idea is to use a soft foam externally rather than make a hollow shell that requires strength to keep water out. Therefore a soft buoyant material that can hold/spring back to shape and light weight seems sensible?

Appearance water pressure and salt water stability are the problems I can think of? Although I believe there is simple solutions around these.

This is going to be used in a small boat with out board engine.

How would I go about finding this material?

 

Can you post a drawing of this craft

 

I'll definitely share photo's showing results.

 

I think it's called soft expanding polyurethane foam. One of the ecologically worst of the plastics. Are you going for a record or escaping Turkey or something? Just curious.

 

One of the ecologically worst is a big consideration.

The original idea was to use a standard brittle core material then cover with the thinnest possible layer of fibreglass. This has its issues which is why soft core is a consideration. I'm guessing expanding foam is generally bad for the environment, so using less is best? Is there not a material number like "alloy 316"? And no, its Noah's arch, but the environmentally unfriendly/exploitative version.

 

Noah's Ark?
There are a number of soft plastic foams. Yoga mats are made with PVC, PE, PUR.
There are a number of issues with plastics of every kind. Besides directly killing critters that eat chunks of it, it breaks down into nano sized particles, shedding toxins all the while. The nanoplastics themselves collect other toxins like DDT, PCBs and others, along with various pathogens, and then enter the food chain on a microbiological level. Passing through cell membranes as they travel up the food chain, they get lodged in fatty tissues and then cause various problems for all us apex predators.
Plastic Pollution http://plastic-pollution.org/
Persistent organic pollutant - Wikipedia https://en.wikipedia.org/wiki/Persistent_organic_pollutant

What are you trying to do anyway? There might be alternatives you aren't aware of.

 

Create a light weight buoyant structure.

Any recommendations on creating the thinnest laminate possible. I have an idea of replacing gel coat (possibility of cracking) with fabric as a finish.

Triaxial cloth as example or quad ... cloth.

The join (hull deck will be below the waterline) similar to a jet ski.

 

I guess a Mylar ballon would be about the thinnest skinned buoyant structure possible. Possibly a soap bubble, but there would be even more serious limitations with that.
It's hard to tell since whatever you're attempting to do seems to be a secret.

Oh, wait...

Maybe skin on frame construction.