T.O. wrote:
I'm wanting to install a bow thruster on a Caliber 40 sailboat.
Can those with thrusters give me some info.


I don't have one... yet... but have been gathering info with the plan of
putting one into our 36' trawler.


Size:
Typical use here is single handing the boat and need help docking. No
current, but may have 10-15 knot crosswind.


Well, the real size limits are what you can physically install in the
boat. Remember you have to put the tube in well below the waterline, at
point where the hull is wide enough, and yet still far enough forward to
gain enough leverage. Get the detailed dimensions of units you're
considering and figure out whether or not you can use that one or if you
have to go down one size.

You may want to consider a retractable thruster. A bit more $$, but you
can put in a more powerful one since the prop deploys lower than the
hull and there's much less of a hit on sailing performance.


Install info:
What size and how long is the cable run on your boat? Do you know the
current draw of your unit?

The smallest Vetus pulls 3KW or 250A/12V. You can get a relay to convert
12V to 24V, that will reduce the amp draw.

I currently have 1/0 cable running up for the windless. Since both would
never be used at the same time, I plan to T off this cable if it will carry
the current.


Since it's a short running DC motor that doesn't have to worry about
high starting load, figure it for 5% voltage drop. The table in the back
of my handy-dandy reference says you can run 200A about 16' on 1/0 cable
with a 5% drop. Remember you have to include the ground leg, the current
has to go there & back!

This is one reason why so many people put an extra battery up forward
for the windlass and/or bow thruster. But then you open a different can
o' worms keeping it charged

Fresh Breezes- Doug King