I remember my Westsail 32 with it's unreliable two cylinder
volvo diesel. I could never count on it starting when I needed it. It always made me nervous coming in to port in marginal conditions or when there were
reefs close by. If the
engine quit at an inopportune moment, disaster could happen.
Having two engines was one of the reasons I liked my
catamaran so much. I always had a spare engine to prevent disaster should one engine go down. In fourteen years of
ownership and cruising around the world, I have never
lost two engines at the same time.
On of my friends had twin 38 hp Yanmars side by side in his fifty foot
monohull cutter. The twin engines were great when he lost one of his props in the
south Pacific.
If I had unlimited finances and was going the custom
monohull route, I would have one built with a dual engine
installation.