If it’s a one-way tunnel, make sure there’s no boat inside. If you have to wait your turn, stay well clear of the entrance.
Switch on your headlight and some interior lights. Some stern lighting will help a following boat to see you, but if it’s a single bright spot or rear navigation light, it might be confused with a headlight by the helmsman of a following boat.
It can be damp in there, so put on your waterproofs and have a waterproof torch to hand.
As you go in, sound one long blast on your horn. Now steer by looking at one side of the tunnel only and keep to a moderate speed. Move the tiller or wheel as little as possible – it’s a common illusion to feel the boat’s being pulled to the side. Watch out for the changing profile, though – tunnels are rarely straight.
Keep at least two minutes (at normal cruising speed) or about 500ft (160m) away from any boat in front of you. If it’s two-way traffic, keep a look-out for oncoming boats and pass slowly on the right.
Some of our tunnels allow canoes and other unpowered craft to paddle through them. But please stay safe and follow our guidance on how to paddling through tunnels:
We don’t allow passage through other tunnels unless it’s part of a managed event which we have given permission for.
Last date edited: 4 March 2020