| SIGNAL | MEANING |
| 1 short blast | I am altering my course to starboard (right) |
| 2 short blasts | I am altering my course to port (left) |
| 3 short blasts | My engines are going astern |
| 5 or more short blasts | I do not consider you are taking sufficient action to keep clear of me; or I do not understand your intentions or actions (ie. what the hell are you doing??) |
| 4 short blasts followed by 1 short blast | I am turning around with my head (bow) swinging to Starboard |
| 4 short blasts followed by 2 short blast | I am turning around with my head (bow) swinging to Port |
| 1 prolonged blast | I am about to get underway, i.e. depart from moorings, jetty or dock entrance |
| 2 long blasts followed by 1 short blast | I am about to overtake on your starboard (right) side |
| 2 long blasts followed by 2 short blast | I am about to overtake on your port (left) side |