1 When to use them: In an out of harbors obvously. In narrow fairways and
rivers or canals. When the speed of sailing is not sufficient to the arrival
goal, unless you are a purist which I'm not. When caught in the doldrums.
When water is low or you have an emergency on board. Here's one trick.
Sail Motoring as opposed to Motor Sailing. When you can't go in the right
direction due to the winds running the prop at slow rpms enhances the
ability of the boat to point high by 10 to 20 additional degrees. (Variable
as to hull and conditions). If that will get you through a narrow passage
between islands so be it. When on delivery jobs with a deadline to meet.
When getting out of the way of or handling the presence of a storm
condition. When you need electricity to listen to the NBA, NFL, America's
Cup or World Cup finals.


2. When not to use the engine. Most of the time. It certainly de-tracts
from the peace of it all. When in a race that doesn't allow it, when you
are down to the last 1/3 of a tank. . . . . .and so on and so forth.

3. Add your own reasons. In the end they will always be 'your own
reasons.'

M.