Rule 35 - Sound Signals in Restricted Visibility

Power driven vessel MAKING WAY - one prolonged blast at intervals not more than 2 minutes

Power driven vessel STOPPED and MAKING NO WAY - two prolonged blasts at intervals no more than 2 minutes

NUC, CBD, Sailing, Fishing, Towing or pushing - Intervals not more than 2 minutes

Fishing and RAM at anchor sound the same signal as underway - One prolonged blast followed by two short blasts

Vessel BEING TOWED or if more than one, LAST VESSEL IN TOW, IF MANNED at intervals of not more than 2 minutes. LONG-SHORT-SHORT-SHORT

Vessels at ANCHOR shall sound the following at intervals of not more than 1 minute
Less than 100m - ring bell rapidly 5 sec
Greater than ring bell rapidly for 5 sec (forward) then gong for 5 sec (aft)
Optional -> SHORT - LONG - SHORT

Vessel AGROUND -> 3 strokes - 5 rapid ringing - 3 strokes - 5 sec gong

Pilot vessel MAY sound 4 SHORT