How to Share Locks on Canals

Knowing how to share locks on canals is one of the most useful skills you can develop as a boater. Sharing a lock can save water, reduce waiting times and make a busy cruising day much smoother for everyone involved.

It can also feel a little daunting if you are new to boating. Two boats, two crews, heavy gates, paddles, ropes and a confined chamber all need a calm and sensible approach.

The good news is that lock sharing is usually straightforward when everyone communicates clearly and works at a steady pace. This guide explains how to do it safely, politely and efficiently on UK canals.

What Does Sharing a Lock Mean?

Sharing a lock means two boats use the same lock chamber at the same time, provided there is enough space for both craft. It is most common on broad locks, where two narrowboats can usually fit side by side.

On narrow canals, locks are built for one narrowboat at a time, so sharing is not normally possible. On broad canals, rivers and some navigations, sharing is often encouraged because it makes better use of the water in the lock.

Before entering any lock with another boat, check the size of the chamber, the length of both boats and whether there is enough room to operate safely. If in doubt, wait and take the lock separately.

Why Share Canal Locks?

Lock sharing has several benefits, especially on popular cruising routes or during dry periods when water conservation matters.

• It saves water: One lock cycle can move two boats instead of one.
• It reduces delays: Queues move faster when suitable boats pair up.
• It shares the workload: More crew can help with gates and paddles.
• It supports good boating etiquette: Sharing shows consideration for other canal users.
• It can be sociable: Many boaters enjoy a friendly chat while working through locks.

However, sharing is never compulsory. If there is a safety concern, a difficult wind, an inexperienced crew or an awkward boat combination, it is better to proceed separately.

When Is It Suitable to Share a Lock?

The first question is simple: will both boats fit comfortably? A typical broad lock may take two narrowboats side by side, but boat length, fenders, bows and stern shapes can all affect the available space.

Sharing is usually suitable when:

• Both boats are travelling in the same direction.
• The lock is broad enough for both craft.
• The boats can enter and leave without touching gates or cills.
• Both skippers are happy to share.
• The weather and water conditions are manageable.
• There is enough crew to operate the lock safely, or both skippers agree on a simple plan.

It may be better not to share if one boat is very new to handling, the lock approach is awkward, one craft is unusually wide, or either crew feels uncomfortable.

Agree a Plan Before You Enter

The most important part of sharing locks on canals happens before either boat enters the chamber. A quick conversation avoids most problems.

Speak to the other skipper or crew and agree:

• Which boat will enter first.
• Whether boats will go in side by side or one slightly ahead.
• Who will close the gates.
• Who will operate the paddles.
• Whether ropes will be used.
• How quickly the paddles will be raised.
• Who will leave first at the other end.

Keep it friendly and simple. A few words such as, shall we go in together, you take the left side and we will take the right, are often enough.

If one crew is less experienced, it is fine to say so. Most boaters would rather know in advance and adjust the pace than discover it halfway through the lock.

Entering the Lock Together

Approach slowly and leave enough space for the other boat to manoeuvre. The boat entering first should move well into position, leaving room for the second boat to settle alongside.

In many cases, one boat will enter slightly ahead of the other. This can make it easier to keep both craft under control, especially if there is a crosswind or bywash near the lock entrance.

Practical tips for entering a shared lock:

• Use low revs and avoid sudden bursts of power.
• Keep hands, feet and boat poles away from the gap between boats.
• Do not rely on fenders to absorb heavy contact.
• Watch the gate, cill, lock walls and the other boat.
• Allow extra time for hire boats, single-handers or nervous crews.

A gentle touch between boats can happen, but heavy bumping is not acceptable. If the approach is going wrong, stop, reverse carefully and reset rather than forcing the manoeuvre.

Positioning Boats in the Lock

Once inside, both boats should be positioned so they are clear of the gates and the cill. This is especially important when going downhill, as the cill can catch the stern of a boat if it is too far back.

Many boaters keep the boats side by side and reasonably central in the chamber. In wide locks, this reduces the risk of one boat being pushed hard against the wall when water enters.

The skippers should remain alert and ready to use gentle engine power if needed. Avoid tying ropes tightly to lockside bollards, as the water level will change and a tight rope can become dangerous very quickly.

If ropes are used, they should be managed by someone who understands that they must be adjusted as the boat rises or falls. Never leave a rope unattended in a lock.

Using Paddles Safely When Sharing

Paddles control the flow of water into or out of the lock. When two boats are sharing, it is wise to operate paddles gradually, especially at the start of the fill or empty.

Fast water can move boats around, push bows out of line or cause unexpected surges. This is more noticeable when boats are side by side.

A safe approach is to:

• Open one paddle slowly at first.
• Watch how both boats react.
• Pause if either boat moves awkwardly.
• Open the second paddle only when both skippers are ready.
• Keep an eye on ropes, cills and gates throughout.

Some locks have strong ground paddles or gate paddles. Local knowledge helps, so listen if the other crew knows the lock. Equally, do not feel pressured to open paddles faster than you are comfortable with.

Communication Between Crews

Good communication is the heart of lock sharing. It does not need to be complicated, but it does need to be clear.

Useful phrases include:

• Are you ready for the paddle?
• Can you hold there a moment?
• We will go out first if that suits.
• Please open that one slowly.
• We are clear of the cill.

Hand signals can help, but make sure everyone understands them. A thumbs up from one person may mean ready, while another may think it means open fully. When in doubt, speak.

A calm tone matters. Locks can be stressful if boats move unexpectedly, but shouting rarely helps. Clear, short instructions are far more useful than panic.

Leaving the Lock

Before opening the gates, agree who will leave first. Usually, the boat with the clearer line or the one positioned slightly ahead will go first.

Do not rush the exit. The first boat should move out slowly and keep clear of the lock mouth so the second boat has room to leave. The second skipper should wait until there is enough space, particularly if the channel outside the lock is narrow.

Once both boats are out, crews should close gates and lower paddles unless local signs say otherwise. On some navigations, instructions may differ, so always follow posted guidance.

Lock Sharing Etiquette

Canal etiquette is mostly about courtesy, patience and common sense. A shared lock works best when nobody tries to take over or hurry others along.

Good etiquette includes:

• Ask before sharing rather than assuming.
• Respect a skipper who says they would rather go alone.
• Help with gates and paddles if you are able.
• Do not criticise inexperienced crews.
• Keep children and pets supervised.
• Leave the lock ready for the next boat where appropriate.
• Thank the other crew before moving on.

If you arrive at a lock where another boat is waiting, ask which direction they are travelling and whether they would like to share. If there is a queue, boaters often pair up naturally, but it is still worth confirming.

Sharing Locks as a Single-Handed Boater

Single-handed boaters can share locks, but it requires extra care and cooperation. If you are boating alone, explain this to the other crew before entering.

Many crews are happy to help with gates or paddles, but they need to know what you intend to do. Agree where your boat will sit, whether you will use a centre line and who will operate each side of the lock.

If you are sharing with a single-hander, be patient. They may need more time to step off, secure the boat or return to the helm. Offering help is welcome, but do not take control of their boat or ropes unless asked.

Common Mistakes to Avoid

Most lock sharing problems are caused by haste or poor communication. Avoid these common mistakes:

• Entering without agreement: Always check that the other skipper is happy to share.
• Opening paddles too quickly: Sudden water movement can push boats about.
• Standing in unsafe places: Keep clear of edges, moving gates and rope pinch points.
• Forgetting the cill: When descending, keep boats forward and watch the stern.
• Using tight ropes: Ropes must move as the water level changes.
• Rushing the exit: Give each boat enough room to leave safely.

If something feels wrong, pause. Lower a paddle if necessary, speak to the other crew and sort the problem before continuing.

What to Do If You Do Not Want to Share

There may be times when you prefer not to share a lock. Perhaps you are new to boating, the wind is awkward, your boat is difficult to handle, or you simply feel unsure.

It is perfectly acceptable to say no politely. A simple response such as, we are still learning so we will go through on our own, is enough. Most boaters will understand.

Safety always comes before speed or water saving. It is better to take a little longer than to put boats, crews or lock structures at risk.

Frequently Asked Questions

Can two narrowboats share every canal lock?

No. Two narrowboats can only share locks that are wide enough. Narrow locks are designed for one narrowboat at a time. Always check the chamber size and do not attempt to squeeze in if space is limited.

Who decides which boat enters the lock first?

The skippers should agree before entering. Often the boat with the easier approach goes first, or the boat already waiting at the lock takes the lead. There is no fixed rule, so communication is key.

Should boats be tied up inside a shared lock?

Not usually tied tightly. Ropes can be useful for control, but they must be handled carefully and adjusted as the water rises or falls. A tight or unattended rope in a lock can be dangerous.

Is it rude to refuse to share a lock?

No. It is fine to refuse if you feel uncomfortable, inexperienced or concerned about conditions. Be polite and clear. A safe separate passage is better than an unsafe shared one.

Who works the paddles when sharing a lock?

Crews should agree this before starting. Often one crew works one side and the other crew works the opposite side. If one boat has limited crew, the other may offer help, but the pace should suit both skippers.

A Calm Approach Makes Lock Sharing Easier

Learning how to share locks on canals is really about awareness, patience and teamwork. Take time to talk before entering, move slowly, open paddles carefully and keep watching both boats until the lock is complete.

With clear communication and a considerate attitude, sharing locks becomes a normal part of canal cruising. It helps save water, keeps traffic moving and often adds a pleasant social moment to the journey.