Sound Signals - Restricted Visibility
You should use sound signals to alert other boaters to your presence in the area, if visibility is restricted (due to fog, rain etc).
The following are examples of sound signals used in restricted visibility:
| VESSEL TYPE | SITUATION | SOUND REQUIREMENT |
| Power Vessel | Underway | Prolonged blast every two minutes. |
| Sailing Vessel | Underway | Prolonged blast + two short blasts every two minutes. |
| Sailing Vessel | Underway but not moving | Two prolonged blasts every two minutes. |
| Any Vessel | Anchored | Five seconds of rapid blasts / bell ringing every minute. |
| Any Vessel | Run aground | Three bell strokes + five seconds of rapid bell ringing + three bell strokes every minute. |
