OMC and Volvo both produced a 2 stroke saildrive unit... neither proved historically reliable and despite the reduced cost vs diesel never really caught on. Most boats originally so equipped now sport outboards (many of them still have the original drive unit in place)
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)