On 23 May 2007 08:41:02 -0700, Chuck Gould
wrote:

My point is that bad fuel isn't a single vs. twins issue.

Many, like my GB49 - but certainly not all, boats with twin engines
also have twin fuel tanks giving a nice measure of extra redundancy.
Twice I have lost one of my engines due to botched on-the-fly filter
changes. It's very reassuring to hear the second engine still purring
along when that happens. Being an old sail boat guy I am somewhat
obsessed with gaining every possible measure of redundancy. I would
definitely want some sort of backup propulsion in a single engine
boat.

There are just too many things that can go wrong. Even single engine
aircraft which are built and maintained to extremely high standards
occasionally experience an engine failure. Single engine commercial
boats and long range trawlers such as the Nordhavns will typically use
parallel filtration, keel coolers and dry stack exhausts to eliminate
frequent problem areas. Even then, the Nordhavns are often equipped
with a small "get home" engine.