9.9hp 4-stroke redux
 

Okay made the decision, almost... Long vs. Extra-long? XL puts another
15cm of shaft body into the water. This is negligible in terms of added
drag, yes? The motor is to be used as an auxiliary drive out through a
well in the stern, aft of the rudder. XL would also reduce the frequency
of the prop coming out of the water if the boat starts hobby-horsing,
although we don't get that kind of wave condition in northern Georgian Bay
that often. With the thrust point that much lower should I consider an
increase/decrease in squat effect under hard power?
Thoughts? Opinions?

9.9hp 4-stroke redux
 

We have a Yamaha 9.9HP 4-stroke on the back of our
Catalina 27, and it has generally worked very
well. However, one of the problems of having an
outboard on a sailboat is that as the boat nears
hull speed the back of the sailboat is much lower
in the water.

At rest, the prop is only four or five inches
under water, and at hull speed, the water is
starting to flow around the bottom of the
powerhead case. This is not a big problem because
you can always just back off on the throttle a
little if it starts getting too low. However, I
have thought that it would be really nice to have
a power unit to raise and lower the outboard.

Don W.

prodigal1 wrote:
Okay made the decision, almost... Long vs. Extra-long? XL puts another
15cm of shaft body into the water. This is negligible in terms of added
drag, yes? The motor is to be used as an auxiliary drive out through a
well in the stern, aft of the rudder. XL would also reduce the frequency
of the prop coming out of the water if the boat starts hobby-horsing,
although we don't get that kind of wave condition in northern Georgian Bay
that often. With the thrust point that much lower should I consider an
increase/decrease in squat effect under hard power?
Thoughts? Opinions?