Home / Seamanship / Sailing manoeuvres and deck work / Locks in a pleasure boat, step by step
Through the lock in a pleasure boat
A lock raises or lowers your boat several metres in a few minutes. Through the lock all is quiet as long as the lines run free, and it turns dangerous the moment a line is tied off while the water keeps moving. Taking a pleasure boat through a lock is not difficult, but it has firm rules.
Wait for the lights
Red means do not enter, green means you may. Hold back until the signal or the lock keeper calls you in, and wait on the waiting pontoon rather than circling off the gate.
Commercial traffic first
Barges and passenger vessels generally have priority. Leisure craft usually follow and take whatever space is left, often astern of the big ship.
Round the bollard and back aboard
Each line runs from a cleat on board, round the bollard or floating bollard and back to the boat. A crew member can then ease or take in, and let go at once if something jams.
Never tie off
A line made fast holds the boat while the water drops, until the boat hangs on it or the cleat tears out. Going up, it drags the topsides hard against the wall. In a lock, lines stay in a crew member's hand.
Before the lock: waiting pontoons, priority and VHF
Larger locks usually have a waiting area for leisure craft. Tie up there rather than circling in front of the gates, and get everything ready in peace. In Germany, conduct at locks on most inland waterways is set out in the Binnenschifffahrtsstraßen-Ordnung, the inland waterway regulations, with separate police regulations for some rivers. In the UK and elsewhere the navigation authority's own rules apply, and the lock keeper's instructions always come first.
Commercial traffic generally has priority. A barge arriving after you may well be locked through before you. Leisure craft are often gathered up and locked together, sometimes alongside a commercial vessel, sometimes in dedicated slots at set times. Patience is part of the job.
Many locks can be called on inland VHF, with the channel usually posted at the lock or given in the pilot book. Only call if your set and your operator's certificate are valid for that waterway and you can still steer the boat safely while talking. Otherwise wait for the lights or use the intercom point where there is one.
Lock signals: what red and green mean
At most locks on the Continent, lights tell you whether you may enter. A single red light means no entry. A green light means you may enter. Two red lights in Germany generally mean the lock is out of service or will not be operating for some time.
Red and green shown together mean: do not enter yet, but get ready, the gates are about to open. Even green on its own is not an invitation to race in ahead of everyone. If commercial vessels are locking through with you, follow them in unless the keeper tells you otherwise.
Leaving calls for the same patience. Wait until the gate is fully open and, where there is one, the signal shows clear. Cast off too early and you meet the last rush of water equalising through the gate, or the wash from the propeller of the ship ahead.
Locking through: lines, bollards and the engine
Come in slowly and go where the lock keeper wants you, or to the next free space along the wall. The lines are rigged before you enter, one forward and one aft, with fenders hung low on the wall side. A boathook within reach makes it much easier to get a line round a bollard.
The line runs from the cleat on board, round the bollard or floating bollard and back on board. A crew member holds the tail, at most with one turn round the cleat, and eases or takes in as the water moves. That keeps the boat close to the wall without ever being fixed to it.
Once the boat is secure, stop the engine unless told otherwise. Exhaust fumes collect in a closed chamber, and a turning propeller stirs the water for everyone. Keep the engine ready to start, though, so you can manoeuvre as soon as you are released.
- Tie up at the waiting pontoon and watch the signals
- Hang fenders low on both sides and rig lines fore and aft
- Enter only on green or when instructed, after commercial traffic
- Lead the lines round the bollards or floating bollards and back aboard
- Engine off or as instructed, ease or take in the lines
- Leave only when the gate is open and the signal shows clear
Going up and coming down: rising and falling locks
In a rising lock the water comes in, often with real force, and pushes the boat forward, back or sideways. Take in the lines steadily and keep clear of the upper gate, where the turbulence is often worst. If the bollards are set in recesses one above the other, move the line up to the next one in good time as you rise.
In a falling lock the water drains away and the lines have to be eased, otherwise the boat ends up hanging on them. Watch the cill astern, the step in the masonry below the upper gate. Lie too far back and the rudder or stern can land on it as the level drops. Marks on the wall often show how far forward you should be.
Either way, hands and feet stay on board. Nobody pushes off the wall with a foot or reaches between hull and masonry. Keeping a knife handy on deck is an old rule of seamanship, so a jammed line can be cut at once if it comes to that.
Self-service and small craft locks
On smaller waterways you will find locks built for leisure craft, often without a keeper. They are worked with pull rods, buttons or switches, and a board at the lock explains the sequence. On many British canals you will instead work the paddles and gates yourself with a windlass. Read the instructions in full before you touch anything.
The principles do not change with self-service: never tie off, keep clear of the gates and only leave when the gate is fully open. If other boats are waiting, take them with you rather than using the chamber alone. Sharing a lock saves water and everybody's time.
Operating hours are often limited and on some waterways seasonal. Check before you set off when the locks on your route are worked, or the day's passage may end unexpectedly in front of a closed gate.
Frequently asked questions
Can I make the line fast on a cleat in a lock?
No. The line goes round the bollard and the tail is held by hand on board so it can be eased or taken in. A line tied off can leave the boat hanging as the water drops or press it against the wall as the water rises.
What does red and green together mean at a lock?
Do not enter yet. The signal announces that the gates are about to open. Enter only on green alone or when the lock keeper signals you in.
Do I have to switch the engine off in a lock?
At many locks this is required or will be requested once the boat is secure. The local rules and the lock keeper's instructions decide. Keep the engine ready to start either way.
How many fenders do I need for locks?
As a rule of thumb at least three a side, hung low, because lock walls are rough and you will not always lie on the same side. A fender board protects against bollard recesses and ladders where round fenders roll away.
Who has priority at a lock?
Generally commercial traffic and official vessels on duty. Leisure craft follow afterwards or are locked through in groups. The lock keeper decides the order.
Do I need a radio licence to use locks?
Not for locking itself. But if you want to use VHF on German inland waterways, you need the appropriate operator's certificate and a set approved for inland use. Without radio you rely on the lights, intercoms or hand signals.
What this has to do with insurance
Locks rarely produce dramatic accidents, but they produce plenty of scuffs: chafe along the topsides, crushed fenders, a stanchion bent on a wall ladder. Most of it can be avoided with enough fenders hung low and a fender board outside them. Have a quick look at hull and lines after each lock; damage spotted straight away is far easier to account for later.
