Seamanship on the Thames

This article is adapted from an article by the Port of London Authority - all rights acknowledged though responsability for edits rests with GYC!

Key rules for sailing on the tidal Thames

As the tidal Thames is linked to the sea, all vessels need to follow the ‘International Regulations for Preventing Collisions at Sea’ (“Col Regs”). You can read the rules in full here. (There are other local byelaws that relate to rights of way with other vessels, which will be explained further below.) The main basic rules are: When navigating in the tidal Thames vessels must keep as near to the starboard side of the fairway at all times, as is safe and practicable, or follow the recommended routes shown on our Recreational Users’ Guide. For the avoidance of doubt, this does not mean that you can cross from one bank to another to tack along the river. If you are crossing the river, it is to get to a set location for a particular purpose (i.e. to leave/get to a mooring) and you must not tack, cross or enter the fairway so as to obstruct another vessel proceeding along the fairway.

• KEEP A GOOD LOOK-OUT at all times, BEHIND YOU as well as in front
• If you find yourself approaching another vessel head-on, you should sound one short blast and keep to the STARBOARD (RIGHT)

When entering the river from a lock, pier or berth do not cross in front of another vessel.

At bridges, use the most starboard arch available to you provided it does not compromise your safety. (See the specific navigation advice for different areas of the river below, for more advice.)

Our byelaws contain rules which supersede some of the International Collision Regulations. For example

• a vessel must not cross or enter a fairway so as to obstruct another vessel proceeding along the fairway.
• a vessel navigating above Cherry Garden Pier must not impede the passage of
• a vessel of 40m or more in length (above Westminster Pier, this length reduces to 20m)
• a vessel engaged in towing