Duralay as sound proofing?

[boatbuilder]

Has anyone tried this duralay stuff to make things quieter? Its called "Duralay Sound Barrier", used for under timber floors and carpets etc.

Its 3mm thick, high density sponge rubber ....it weighs 3kg per square metre. Ya think it would work if I put two or three layers of it over the engine bay and on the sloped bit under the rear seat?

 

[gninnam]

Isn't it a bit naff with water though, as in soaks it up :?:
Other wise sounds like a good one