Each boat is a bit different, and each captain
has to decide when it's beneficial.
On passages with my 42' sloop
, I tend to motorsail whenever I can AND where I can't make decent time under sail alone. When to turn on the motor
is determined by conditions and, yes, schedule. Generally, on long passages if my speed under sail alone falls below about 4 knots for very long, I tend to crank up the iron genny. Then, I leave the sails
up so long as they are adding anything to boat speed and/or reducing unpleasant motion.
I find that the genoa
alone can add considerable speed when motoring, depending of course on wind
and sea conditions. My boat doesn't motor
particularly well, with cruising speed well under hull speed
(6.5 knots motoring vs. about 8.2 knots hull
speed). The addition of any sail area tends to get me up closer to hull
speed and, of course, reduces fuel consumption