"Capt John" wrote in message
oups.com...

Tamaroak wrote:
I'm thinking of putting a bow thruster in a 36" trawler. Has anyone read
any studies or done any research on what this hole and the subsequent
tunnel might do to its fuel economy?

Capt. Jeff

Jeff

Bow thrusters are supposed to be mounted such that, at crusing speed,
the unit is out of the water. This may not be practical on some very
slow moving boats that do not sit bow high at cruse.

John


Maybe on some boats, but most I've seen are on cruising type hulls that
don't lift the bow enough to get the thruster tube out of the water (other
than in higher sea states). As someone else mentioned, a proper
installation will include a flair on the tube opening (both sides) that
diverts the water away from the tube while underway at speed. I have a
Navigator 4800 Classic (52' LOA) and had a bow (and stern) thruster
installed by the dealer. Made absolutely no difference in the boat's top
speed (23 knots) or cruise performance.

RCE