Hi Tim, We have a "Ferry" three cylinder two-stroke here with a Marshall blower (Rootes type) for scavenging. They were designed for the 1950s Liverpool Class lifeboats, everything is a one off, must have cost a fortune. Complete unit with gearbox, has snorkels so that it will run underwater, interesting little lump.
Apparently they were not that successful and a lot were removed in the
60s and sold on.Cheers Paul