Mascoat but there are others also. There is a thread or two here on the site. Marinauts used this material for a bit. They are nice folks but this is a large application material but they have sold smaller quantiles. It can be brushed or rolled but a strong airless is best. Two to three coats is likely optimal and some folks have added a latex overcoat to make it easier to clean but that cuts down on the soundproofing qualities. In my mind, much better than glued on foam, liners, or the like. Also, real vents and dry heat, fans, and did I mention ventilation? On my last boat I used a box fan over the forward hatch (110V) with a small thermostatically controlled heater from Walmart (also 110V), and the the boat cover well off the deck (I have been called something like the word "deckhead" but I forgave that person. Bob Jarrard
https://www.mascoat.com/marine-coatings-applications.html