Bow Thruster Basics

Dean Wiley wileyde at
Wed Mar 4 20:05:43 EST 1998

Wil Andrews wrote:
> Purpose of the Thread
>      If this thread is of interest, it will be because you have a
> bow-thruster on your boat or are
> interested in putting one on your boat.  This will be about how to use the> captnwil at

Having only .001% of the experience of Cap'n Wil and, more importantly,
having limited operational experience with our new bow thruster, I
venture to submit the following early observations:

1. We have fitted a Wesmar 10hp 24VDC bow thruster to our new twin
engine Grand Banks 42 FLOATBOAT..

2. To generate 24 volts a new 8D battery and a "series/parallel switch"
was installed.  We elected to install this in combination with the
port-side engine start battery thus rendering both batteries out of
service for house use since they will support 24 volt potential when the
switch to use the bow thruster is engaged.  Another 3 8D batteries feed
the inverter and starboard engine, but that is another story.

3.  The boat can parallel park.  In the example of a port side tie up,
one can leave the dock by putting the starboard shifter forward, the
port in reverse, engage the bow thruster to starboard and move to
starboard parallel to the dock.  I imagine the best benefits to be: a.
pushing off a lock wall, leaving a parallel docking situation forwards
rather than rearwards, and overcoming onshore winds that pin the boat to
the dock.  Mounting the dock is the converse of the foregoing.  Backing
in a slip with offshore pilings to hold the bow lines is also easy to
manage by using the thruster to lay the bow along side each piling in

4. The duty cycle of the thruster guaranteed by the manufacturer is 1.5
minutes.  We have come close to this in limited testing but have not yet
found a need for the thruster that exceeds about 10 seconds.

5. When we get more familiar with the equipment, we imagine that the
thruster will help us to round tight corners, teach us to leave the dock
with greater ease in forward or reverse and allow us to overcome the
rare "emergence situation" where the boat is suddenly blown or carried
by current in an unexpected direction.

First impressions are positive.

Dean Wiley

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