Meaning Of Boat Whistles

1 LONG: I am directing my course to starboard (right)

1 EXTRA LONG BLAST 8 SECONDS OR MORE: Vessel leaving dock or wharf

1 LONG AND 1 SHORT: Your signal is understood and is satisfactory to me.

1 LONG AND 2 SHORT: Master salute

2 LONG: I am directing my course to port (left)

2 LONG AND 2 SHORT: Call for dispatch to American Locks

3 LONG AND 2 SHORT: Call for dispatch to Canadian Locks

1 SHORT: Cast off lines at dock or in lock

2 SHORT: Stop vessel in lock with winches and propeller

3 SHORT: Vessel moving in fog

3 SHORT: Check speed of your vessel

5 OR MORE SHORT SOUNDED RAPIDLY: DANGER!!!