Introducing ButylMAT Boat Sound Deadening. Our Newest Boat Soundproofing Development When looking at other boat insulation suppliers and conducting our research for the launch of ButylMAT boat sound deadening into the marine market we believe we found a gap in the market for a sub 2mm thick soundproofing product which takes on the noise emited from diesel engines with ease. As many boats including narrowboats and barges have little space left around the engine bay for additional products which w