My advise to know when your sail trimming is correct. Would be to join a
racing club. Not only will you get the maximum speed. You will also learn
how to sail at peak performance all the time.
Buy a bung and clean your impeller often. Then bung keeps the water from
gushing in when you remove the impeller from the thru hull.

Jack
"Parallax" wrote in message
m...
A

Useless Idea #3729
s Y'all know, I dislike expensive gadgets and that extends to knotlogs
with their always fouling impellers but I would really like a
knotmeter that will help me really tell when my sail trimming is
helping (I admit, I really can't tell most of the time) and the
response time of even GPS is suspect. However, my little "KNotstik"
that drags a weighted drag behind with a spring in a cylinder has TOO
SHORT a response time and responds to every wave that passes. So, I
propose to give he Knotstik a longer response time by making the
indicator fit tighter in the cylinder and closing off the end through
the cord with the drag passes making it a sort of damper with air as
the damping fluid. This way, it doesnt respond to very fast
transients but only to longer increases in speed.

Any better ideas?