Using a Bow Thruster

Exercise MA2 – Move the Bow Sideways:

With your stern to the wind, or on a calm day and the boat is at a standstill next to a buoy, engage the bow thruster for 1 second to starboard.

What you learned

The bow of the boat moved to starboard while the stern remained still or perhaps moved slightly to port. This is because the boat will tend to pivot about a point slightly rear of the keel (due to the drag of the rudder as well).

Ah, but what about using the two methods in combination?

Exercise MA3 – Moving the Boat Sideways:

With your stern to the wind, or on a calm day and the boat is at a standstill next to a buoy, put the wheel hard over to port, engage forward for 1 second, and engage the bow thruster to starboard. Note we say port thrust to move the bow to port and starboard thrust to move the bow to starboard.

What you learned

The whole boat moved laterally (VIF-ed) to starboard.

Exercise MA4 – Experiencing Combinations of Engine power and Bow Thruster:

Play with the bow thruster and get a feel for the bow sideways movement versus the pivoting point about which the boat moves. Experiment with the port thrust and reverse to use prop walk to vector the boat to port. Spin the boat using starboard thrust and wheel to starboard. Lock the wheel to starboard and use the port thrust and a combination of forward and reverse gear to prevent any appreciable forward momentum gain to move the boat continuously to port. Try the same to move the boat laterally to starboard; while not as effective as to port due to prop walk, you can still do it.

What you learned

You can spin the boat on its own pivot point. You can move the boat sideways. Now also try these exercises in high wind conditions at various angles to the wind.