Yachtsman's guide

The principal deep water navigational channels within the statutory limits of the Port of Southampton are well marked by buoys and lights. These channels are in constant use by commercial vessels, including large deep draught tankers (VLCCS), container ships, ferries and other traffic.

Recreational users of the harbour are advised to keep well clear of these main channels whenever possible, and use the recommended crossing areas. When main channels have to be crossed, this should be done as nearly as practicable at right angles. AVOID CROSSING THE BOWS OF ON COMING COMMERCIAL TRAFFIC.


Large container ships and VLCCs, in particular, have very restricted visibility for quite a distance ahead when carrying a deck cargo of containers. You may be able to see her clearly, but can she see you?

Some facts you should keep in mind:
  1. Most of the commercial vessels you meet will have a UK pilot on board regardless of the ship’s flag. They will be listening to VHF R/T channel 12.
  1. Most large ships travel at a manoeuvring speed of between 10 to 15 knots whilst in the Solent and Southampton Water. The lower limit will vary from ship to ship and is “as safe navigation permits”.
  1. For various reasons, ships travel faster than you might think, even in congested areas.
  1. Light, partially loaded or unevenly trimmed ships may require to maintain a higher “as safe navigation permits” speed in order to remain under full control.
  1. It takes less than 10 minutes for a fast ship to reach you from the visible horizon in clear weather, and in hazy conditions it takes a lot less. At 10 knots, a ship travels 1 nautical mile in 6 minutes; at 15 knots it takes only 4 minutes.
  1. Large deep draught ships cannot easily avoid small craft in narrow channels – it is up to you to stay clear.
  1. A ship that is slowing down does not steer very well; it needs the propeller action on the rudder to respond. When the ship’s engines are put “full astern” its manoeuvrability will be affected. Remember that it takes time and considerable distance for a ship to stop.
  1. There are numerous other small vessels operating within the Port of Southampton. Watch out for ferries, hydrofoils, tugs towing barges (especially at night, when unlit barges may remain invisible).

    Remember that a towing cable may be partly submerged and therefore extremely dangerous.
What can you do?
  1. Avoid sailing in the commercial ship channels, especially in poor visibility. Obey Rule 9 of the ColRegs for conduct in narrow channels by keeping to the starboard side of the channel and crossing only when this does not impede the passage of a large vessel that can safely navigate only within the narrow channel.
  1. Do not underestimate the speed of ships. If you boat is slow, allow sufficient time to take effective evasive action in the vicinity of large ships.
  1. Be visible. At night make sure your navigation lights can be seen. If you see the navigation lights of a vessel and you think you have not been seen, get out of the way. Use torches, search lights or a spotlight on sails, or fire a white flare to indicate your position. Carry a radar reflector high on your boat. Remember, from the bridge of a loaded container ship or large tanker, the captain or pilot will lose sight of you a third of a mile ahead, although you can see the ship at all times!
  1. Be alert. Look around every so often, especially astern.
  1. Keep watch at night. Even on a clear night you will have difficulty seeing a big ship approach. You might see it first as a black shadow against a background of shore lights, or as a growing shadow – at that point you are not far apart. Remember that your lights will not be easily spotted from the ship.
  1. Watch the ship’s lights. If you see both sidelights, you are dead ahead – MOVE OUT FAST. Be aware that ships alter course at WEST BRAMBLE and CALSHOT. You must be sure of your position and be aware of other vessels operating around you.
  1. Know whistle signals. Five or more short blasts on the whistle is the “Keep Clear” signal. Check and see if it is for you - and if it is - GIVE WAY. Three short blasts means “My engines are gong astern”.
  1. Know flag signals and shapes. Large ships proceeding seawards will fly International Code Flag ‘E’ over the answering pennant which indicates that the vessel will turn to port at the West Bramble buoy and make for the Nab (East). A vessel displaying the answering pennant over International Code Flag ‘W’ will indicate that the vessel will depart the Solent via the Needles (West). A large ship which displays a cylinder on her yardarm during the day or three red lights in a vertical line at night indicates that the ship is severely restricted in her manoeuvrability. Please give her a wide berth.
  1. Keep your VHF R/T tuned to channel 12, the Port working frequency, and listen for traffic information from Vessel Traffic Services, Call Sign VTS.
If you believe you have not been seen or you are unsure of a ship’s intentions, call them on channel 12, then shift to a working frequency (6 or an alternative) for internship safety messages.
In the time it took you to read this far, a ship cruising at 15 knots would have travelled one nautical mile.