Using locks with a boat: instructions, rules and checklist

A high chamber wall ahead, other boats alongside and a changing water level: your first lock calls for attention. With lines prepared, clear crew duties and an understanding of the sequence, you can concentrate on the manoeuvre.

This guide explains how to use locks with a leisure boat or houseboat on German inland waterways. It covers contacting the lock, the relevant signals and handling your boat when locking uphill or downhill. Always follow the regulations for the waterway you are using and the lock operator’s instructions.

How does a lock work?

A lock connects sections of waterway at different levels. The higher section is the upper reach, and the lower section is the lower reach. Between them lies the lock chamber, with gates that can be closed. Your boat remains afloat throughout and rises or falls with the water level.

The exit gate can open only after the water levels have equalised. Even then, wait for explicit permission to leave: an open gate alone is not a departure signal.

Preparation: what to check before your first lock

Before setting off, check the ELWIS lock information. It provides operating hours, contact details and information on closures. Current notices to inland shipping may contain restrictions that override the regular operating hours.

• Route and boat dimensions: Is your boat suitable for the planned route and lock, taking its superstructure, draught and beam into account?
• Contact details: Note the lock’s name, telephone number and, where specified, VHF channel.
• Extra time: Allow for waiting. Traffic, boats travelling in the opposite direction and operational requirements can delay your passage.
• Equipment: Prepare sound bow and stern lines of sufficient length. Their length must suit the change in water level and the intended line arrangement.
• Crew: Agree who will steer and who will handle each line. Everyone involved should understand the commands “pay out”, “take in” and “stop”.

Put on lifejackets, wear shoes with a non-slip sole and keep deck walkways clear. Children should remain supervised in a safe place. Rig fenders on both sides of the boat in good time so you are protected if assigned a different position. Adjust their height to suit the hull and chamber wall.

Using a lock: step by step

1. Approach slowly and make contact

Reduce speed early and look for the marked leisure-boat waiting area. Keep the entrance and other vessels’ routes clear. Contact the lock as directed locally, using VHF, telephone, intercom or the request control. Give your boat’s name, type, position and direction of travel.

If your boat carries a radio installation for the nautical information service (Verkehrskreis Nautische Information), it must be set to receive on the channel specified for the lock while in the lock area. Overtaking is also prohibited in the lock area. The details are set out in Section 6.28 of the German Inland Waterways Traffic Regulations (BinSchStrO).

2. Wait for permission and your turn

When sharing a lock with larger vessels, small craft enter after them and only when called forward or given a specific signal authorising entry. Do not simply follow a cargo vessel into the chamber. Observe Section 6.29 BinSchStrO and the instructions given at the lock.

Where a separate boat lock is available and suitable for your boat, the applicable rules require you to use it unless the lock operator directs otherwise. Let vessels leaving the lock pass first.

3. Enter under control and take your position

Proceed slowly enough to stop your boat safely. Keep clear of other vessels and observe your assigned position and the marked chamber limits. Expect propeller wash behind large vessels. Never use hands or feet between the hull and the wall to fend the boat off.

Stop the boat before securing its lines. Floating bollards must not be used to stop a boat that is still moving. This rule and the requirement to maintain sufficient clearance are set out in Section 6.28 BinSchStrO.

4. Tend the lines and watch the water level

Lead bow and stern lines around suitable mooring points and back on board. When using fixed bollards, the working end must remain free to be paid out or taken in under control. Do not secure it with a knot that creates a fixed-length connection. Stay at your line throughout the change in water level.

The official lock guidance leaflet describes leading the line around a cleat on board so that your hands do not take the full load. Never wrap a line around your hand, arm or body, and never stand inside a loop of rope.

After securing the boat and until exit is authorised, you must generally not use propulsion or the bow thruster to manoeuvre. Section 6.28 BinSchStrO permits brief use for safety reasons. This is not blanket permission to motor against the lines during a lock passage.

5. Leave only when authorised

Keep the boat secured until exit is authorised and it is your turn. Bring every line fully on board and keep lines clear of the propeller. Leave the chamber slowly and maintain your distance; vessels ahead may create further currents.

Lock signals: what do red and green mean?

This overview covers the entry signals under Section 6.28a BinSchStrO. Where separate, clearly designated signals for small craft are provided, those signals apply to your leisure boat.

For departure, follow the relevant exit signal or the lock operator’s explicit instruction. Where no signal is provided, do not decide to leave solely because the gate is open. Contact the operator if anything is unclear.

Locking uphill: adjust the lines as the water rises

When locking uphill, water flows into the chamber. The resulting currents can move your boat even when you have very little headway. Use the prepared lines to control its position while watching the fenders, neighbouring boats and mooring points.

If the lines lead to a fixed bollard above your boat, take them in as needed while you rise. If using wall bollards arranged at different heights, transfer to a suitable higher point in good time. The basic principle is explained in the official guidance leaflet.

Coordinate any transfer with the other crew member so that the boat remains secured. If you cannot reach a mooring point safely, tell the lock operator early. Do not jump between the boat and the chamber wall.

Locking downhill: pay out the lines and watch the cill

When locking downhill, your boat descends. Pay out lines attached to fixed bollards under control and keep enough spare line ready. If a line is too short or jams, the boat can become suspended from it and develop a dangerous list.

The cill is the threshold beneath a lock gate. At the upper gate in particular, a boat’s stern can settle onto the cill as the water drops if the boat is too close to the gate. Keep the entire boat, including its bathing platform and drive, clear of the marked cill area. Follow the local markings and instructions; a universal distance in metres is not a suitable substitute.

Fixed bollards, floating bollards and self-operated locks

At a fixed bollard, the difference in height between your boat and the mooring point changes. You must adjust the line and may need to change mooring points. A floating bollard moves with the water level. Still check that it moves freely and that the lines remain clear.

Use only the designated mooring facilities. A ladder is not automatically an alternative to a bollard. Keep access ladders clear and ask the operator where to secure your boat if no suitable position is within reach.

At a self-operated lock, read all instructions before activating the equipment. Establish how to request passage, when you may start the cycle and where the intercom and emergency stop are located. Controls differ between installations; a button or lever does not have the same function at every lock.

Checklist: is your boat ready for the lock?

• Operating hours, current notices and contact details checked.
• Waiting area, direction of travel and designated chamber confirmed.
• Lifejackets on and crew duties assigned.
• Fenders correctly positioned; bow and stern lines clear and long enough.
• Entry signal received, including any separate permission required for leisure boats.
• Mooring points, chamber limits and cill markings identified.
• Lines tended continuously throughout the change in water level.
• Exit permission received and all lines brought on board before departure.

Damage in a lock: which insurance might apply?

Contact with the chamber wall is a different type of loss from damage to a neighbouring yacht. Before your trip, check which risks your policy covers:

• Your own boat: Boat hull insurance may cover insured damage to your own boat. Boat liability insurance may respond to valid claims by third parties. You can review both types of cover in the boat insurance comparison.
• Charter boat: Check the charter company’s insurance, your contractual excess and any supplementary skipper liability insurance.
• Charter deposit withheld: Charter deposit insurance may reimburse a lost deposit within the agreed limits following an insured incident.

Whether a particular loss in a lock is insured depends on the circumstances, policy terms, excesses and exclusions. After an incident, deal with safety first, inform the lock operator and document the damage. On a charter boat, also notify the charter company and follow your insurer’s reporting requirements.

Sources and information date

Information checked: 29 September 2026. Sources: ELWIS lock information, Section 6.28 BinSchStrO on conduct at locks, Section 6.28a on lock signals, Section 6.29 on the order of passage and the official lock guidance leaflet. These rules apply within their respective geographical and legal scope. Check local regulations and current directions for your particular waterway as well.

Summary

Prepare the manoeuvre, assign crew duties and work at a pace that suits your boat, crew and the lock. As the water level changes, keep your attention on the lines and maintain control of the whole boat. Clear communication and enough time help make even your first lock passage manageable.