This has been brought up before but heres what I did.
I used one inch foam that you can get at home depot in sheets. Myself I used some some stuff salvaged from a dead rv and cut it into pieces that fit the bulkheads inside the cabinets and lined everything inside the boat with a thickness of foam. I put in on the cabin sole with rug over it. Two pieces between the forward end of the engine and the motor box itself. I put it in the bilge near the water intake. Because I thought the noise was transmitted forward I blocked the back of the storage area under the bunk. Its now quiet or quieter. I held things in place with good quality duct tape or just wedged in place. My used foam had a blue tint to it and was a bit more closed cell. I worked with pieces about two foot by two foot. Cardboard was used for templates. This may not be pretty but it does work.
Bob Heselberg Eatonville Wa
