I have an early 70s 27 foot sailing boat with a single cylinder 10HP
Yanmar diesel. This is in a box formed of 1/2" ply on each side with a
removable front and lid. The current soundproofing seems to be some kind
of foam or mat held in place by perforated hardboard. What suggestions
to people have rather than paying £50 per sq m for a lead sandwich foam?

Regards,
Jerry

1973 Marcon Sabre 27 bilge keel
Plymouth, UK