INTERNATIONAL RULES FOR PREVENTING COLLISIONS AT SEA
-PART C
RULES 20 - 31
2008
General
• Instruction in the various navigation light layouts that may be experienced.
• In all examples define what action you would take if the grey mast indicates your vessel’s bow, and the other vessel is on a steady bearing.
Rule 20 - Application
Rule 20 - Application
• Lights shall exhibited from sunset to sunrise, and no other lights shall be exhibited that may be confused with the defined lights.
• Navigation lights shall also be exhibited during periods of restricted visibility
Rule 21 - Definitions
Navigation Lights
1. Masthead light
2. Port side light
3. Starboard side light
4. Stern light
5. Towing light
Rule 22 - Visibility of Lights
Rule 22 - Visibility of Lights Masthead
light Sidelight Sternlight Towing light All round
red white, green or yellow light
Length 50 metres or more
6 miles 3 miles 3 miles 3 miles 3 miles
Length less than 50 but 12 metres or more
5 miles 2 miles 2 miles 2 miles 2 miles
Length less than 20 but 12 metres or more
3 miles 1 mile 2 miles 2 miles 2 miles
Length less than 12 metres
2 miles 1 mile 2 miles 2 miles 2 miles
Rule 23 - Power-driven Vessels Underway
Power driven vessel, less than 50m in length, underway and making way, seen from starboard
Power driven vessel probably greater than 50 metres in length, seen from ahead.
Power driven vessel probably greater than 50 metres in length, starboard side open
Power driven vessel maybe more than 50 metres in length, port side open
Power driven vessel maybe more than 50 metres in length, port side open
Submarine, underway and making way, seen from starboard (Yellow all round light 90 flashes per minute)
Submarine underway and making way, port side open (Yellow all round light 90 flashes per minute)
Non displacement vessel making way, port side open (Yellow all round light 120 flashes per minute)
Non displacement vessel possibly greater than 50 m in length, underway and making way, port side open (120 flashes per minute)
Rule 24 - Towing and Pushing
Towing vessel 50m or less, with length of tow 200m or less, seen from ahead. Tow too small to be seen from this aspect.
Tug with tow less than 200m, starboard side open
Vessel less than 50 metres in length engaged in towing, with length of tow less than 200 metres seen from port
Vessel less than 50 metres in length engaged in towing, with length of tow less than 200 metres seen from port
Vessel engaged in towing less than 50m in length, with length of tow greater than 200m, starboard side open
Vessel engaged in towing possibly greater than 50m in length, with length of tow less than 200m, starboard
side open
Tug with tow less than 200m, port side open
Vessel engaged in towing, with tow, seen from aft
Vessel engaged in towing, with tow, seen from aft
Tug with tow less than 200m, starboard side open, pushing but not composite unit
Tug with tow exceeding 200 metres, starboard side open, towing a log boom
Vessel engaged in towing, probably a log boom, seen from astern
Vessel engaged in towing possibly greater than 50m in length, with length of tow greater than 200m, starboard
side open
Vessel engaged in towing, seen from astern, and the tow seen from starboard
You could be in risk of collision, and in grave danger
Rule 25 – Sailing Vessels Underway and
Vessels Under Oars
Sailing vessel, port side open, showing optional lights
Sailing vessel seen from ahead
Sailing vessel less than 20 metres in length seen from ahead, with combined lantern at masthead
Sailing Vessel from astern
Sailing vessel with mast head lantern, seen from starboard
Rule 26 - Fishing Vessels
Fishing vessel engaged in fishing under 50 metres in length, starboard side open
Fishing vessel engaged in trawling, underway less than 50 metres in length, port side open
Fishing vessel less than 50m in length, engaged in fishing, seen from starboard
Fishing vessel engaged in fishing under 50 metres in length, port side open
Vessel engaged in trawling, underway maybe 50 metres or more than in length, seen from ahead
Vessel engaged in trawling, underway maybe 50 metres or more in length, port side open
Fishing vessel engaged in trawling, underway less than 50 metres in length, seen from ahead
Fishing vessel engaged in trawling, underway possibly greater than 50 metres in length, seen from ahead
Fishing vessel engaged in trawling, less than 50 metres in length, with outlying gear, starboard side open
Vessel engaged in trawling, underway less than 50 metres in length, port side open, with gear out towards white light
Two fishing vessels engaged in fishing, one with outlying gear, seen from starboard side
Rule 27 - Vessels Not Under Command or Restricted in Their Ability to Manoeuvre
Vessel not under command, underway
Vessel, not under command, underway and making way, seen from ahead
Vessel not under command, underway and making way, starboard side open
Vessel underway and making way, not under command, port side open.
Vessel probably over 50 metres in length, restricted in ability to manoeuvre, starboard side open
Vessel engaged in towing, under 50 metres in length, restricted in ability to manoeuvre, starboard side open, probably a log boom
Vessel engaged in towing less than 50m in length, with length of tow greater than 200m, restricted her ability to
manoeuvre starboard side open
Vessel restricted in her ability to manoeuvre, head on, with obstructions on her starboard side
Vessel restricted in her ability to manoeuvre, head on, with obstructions on her starboard side and clear
on her port side
Vessel restricted in her ability to manoeuvre, seen from astern, underway or at anchor, with obstruction on her port side
Minesweeping vessel, probably 50 metres or more in length, port side open
Two power driven vessels, probably greater than 50 metres in length, underway and making way, restricted in their ability to manoeuvre, seen from starboard - probably replenishing at sea
Rule 28 - Vessels Constrained by Their Draft
Power driven vessel maybe more than 50 metres in length, underway and making way, starboard side open,
constrained by her draft
Power driven vessel maybe more than 50 metres in length, port side open, constrained by her draft
Power driven vessel, seen from astern, constrained by her draft
Rule 29 - Pilot Vessels
Vessel on pilotage duty, seen from ahead
Vessel on pilotage duty, underway, starboard side open
Vessel on pilotage duty underway, and making way, seen from astern
Pilot vessel, port side open, alongside power driven vessel possibly greater than 50 metres in length, both
underway and making way
Rule 30 - Anchored Vessels and Vessels Aground
Vessel at anchor possibly greater than 50 metres in length, starboard side
Vessel at anchor, with decklights, or power driven vessel underway and making way, showing improper decklights
Vessel aground, seen from either end It could also be a vessel not under command seen from astern
Vessel aground, starboard side open
Vessel aground, port side
Rule 31 - Seaplanes
Seaplane, seen head on
Others
Power driven or sailing vessel underway from astern