Communications with Marine Services for locking operations

In person

The Marine Services Supervisor will be pleased to meet boat owners during the tidal watch to explain the workings of Cumberland Basin and discuss plans for arriving and sailing. The Watch House is on the south side of the Entrance Lock. Local charts and Notices to Mariners are on display.

By phone

Phone 0117 927 3633. Between tidal watches callers will be connected to an answering machine, which gives useful information about the following tide. You will be invited to leave a message for the Marine Services Supervisor and should be prepared to state:

  1. Your name and phone number.
  2. The name and dimensions of your craft, including air draught.
  3. Whether or not you will be using VHF communications or mobile phone.
  4. The date and estimated time of your arrival or sailing.

VHF Radio

During tidal watch, direct communication may be established with the Marine Services Supervisor from within the City Docks or from the River Avon upstream of Black Rock lights. Use low power only calling City Docks radio on Channel 14. You may be asked to work Channel 11 if Channel 14 is busy.

Entrance information

From the mouth of the River Avon, the Cumberland Basin Entrance to Bristols Floating Harbour lies 10.5km up river. The entrance lock is on port side approximately 0.7km beyond the historic Clifton Suspension Bridge.

Cumberland Basin is the seaward approach to the Floating Harbour, passing through the Entrance Lock, Cumberland Basin itself and the Junction Lock. There are swingbridges across Cumberland Basin just beyond the Entrance Lock and Junction Lock. Navigation in the harbour and bridge clearances.

The maximum size of vessel which can be accepted is determined by conditions in the river and the dredged depth in the harbour. The maximum dimensions are (note that confirmation from the Marine Services Supervisor is required):

  • Length: 70 metres (LOA)
  • Beam: 14 metres
  • Draught: 4.50 metres
  • Masthead height: 29 metres (M5 Bridge charted height at HAT)

Draught may also be limited by under-keel clearance in the river.

Cumberland Basin becomes tidal when the level of water in the river is above the level in the Floating Harbour. When this happens stopgates are placed across Junction Lock to prevent the level of water in the Floating Harbour from rising, and Junction Lock is then closed to navigation. Locally known as stopgate tides or on a level.

Tides of 9.6m and over are stopgate tides, but tides of 9.1m to 9.6m may become stopgate tides if the level of tide is higher than predicted or if the level of water in the Floating Harbour is below normal level. The Stopgate Closure Table gives the times of closure of the stopgates for various heights of tide under normal conditions. Vessels wishing to enter or leave the harbour during this period should obtain the free Cumberland Basin Tide Table for detailed information on stopgate closures and bridge embargos or contact the Marine Services Supervisor at the start of tidal operations.

Heights of tides throughout these pages relate to the Outer cill of the Cumberland Basin Entrance Lock. Deduct 3.1m from the heights given in Arrowsmiths Bristol Channel Tide Table under the heading Avonmouth King Road.

Boat owners are asked not to leave their vessel unattended in Junction Lock or Cumberland Basin at any time. Any such vessel may be removed by the Marine Services team.

Vessels waiting to transit Junction Lock and Cumberland Basin may tie up at the Pooles Wharf transit berths. Due regard should be given to any published events taking place in the area.

Times of locking operations

The Marine Services Supervisor is on duty from three hours before high water until 48 minutes after, although lockings do not normally take place after high water. See the Vessel Locking schedule below.

Road traffic has priority at the swingbridges during rush-hours, and these times are set out under Swingbridge Restrictions.  Navigation can be affected both by stopgate and bridge closures, although this is more likely to happen in the morning than in the evening.

Craft intending to sail on stopgate tides must be in Cumberland Basin at least half-an-hour before the published stopgate closure time. If a swing of Junction Bridge is required, vessels must be at Junction Cut, one hour before.

If you wish to sail on the first locking outwards, it is advisable to give at least 12 hours notice to the Marine Services Supervisor in order that the lock can be filled in readiness at the start of the tidal shift.

The following times are approximate; consult the Marine Services Supervisor in advance whenever possible for further information.

Vessel Locking schedule: time before high water
First 2 hours 50 minutes 2 hours 35 minutes
Second 1 hour 40 minutes 1 hour 25 minutes
Third 30 minutes 15 minutes

This schedule operates when there's sufficient demand and providing it does not conflict with the requirements of other classes of vessel.

These times are subject to alteration by the Marine Services Supervisor.

Stopgate closure
Height of high water (m)From (before high water)To (after high water)
9.60 30 minutes 20 minutes
10.10 1 hour 40 minutes
10.60 1 hour 20 minutes 55 minutes
11.10 1 hour 35 minutes 1 hour 10 minutes

Tides of less than 9.6m predicted height may be subject to stopgate closure if the height of the tide is greater than predicted or if the harbour level is lower than usual.

Stopgate times are frequently half an hour earlier than anticipated. Departing vessels should present themselves in Junction Lock one hour before the stated times.

Road traffic has priority at the swingbridges during rush-hours and these times are set out below.

Swingbridge Restrictions

The Cumberland Basin bridges are not swung at the following times:

  • Mondays to Fridays (except public holidays) between 8am to 9am and 5pm to 6pm.
  • 30 minutes either side of these times, road traffic has priority on all bridges and there may be shadow periods at the discretion of the Marine Services Supervisor.

The clearance beneath the bridges to enter the harbour from seaward are:

  • Plimsoll Bridge 5.9m M.H.W.S and 5.8m above Harbour Level
  • Junction Lock Bridge 2.5m above Harbour Level

Arriving or sailing 'on the level' and 'stopgate times'

On tides of 9.6m and over, the Entrance Lock can be navigated 'on the level', that is, there is no requirement to lock through as the gates are open to the river and the lock and basin become tidal.  A level will occur anytime between 1 hour and 10 minutes to 20 minutes before high water and 15 minutes to 1 hour and 10 minutes after high water depending on the height of the tide and the prevailing conditions.

Vessels should either aim to arrive on the first inward locking in order to proceed through into the harbour, or wait for a 'level' negating the requirement to lock through but necessitating a short wait in the Basin to allow stopgates to come off and access to the harbour.

Arrival procedure from seaward

Vessels are strongly advised to give 24 hours notice of intention to arrive at Bristol Harbour.

When approaching the entrance to the River Avon leave Avonmouth South Pier lighthouse close to your port side. Be aware that at 3 hours to High Water the tidal flow crossing the entrance can reach 4 to 6 knots. Keep the Swash Bank transit lights in line until the St. Georges transit lights are in line. Leave the Hoveringham buoy to starboard. Be sure not to enter the river without sufficient depth of water available for your vessel. For larger sailing vessels consideration should also be given to sufficient air draft clearance for passing under the M5 Motorway Bridge.

The speed limit in the river for vessels with a draught less than 2 metres is 9 knots over the ground and for those with a draught of more than 2 metres 6 knots. However, when passing pills and creeks where boats are moored you should reduce your speed to minimise wash.

Recreational craft should avoid impeding the passage of large vessels transiting the river. This is most important when rounding bends, particularly Horseshoe Bend. Large vessels, particularly those carrying passengers will have an escort tug in attendance.

You should avoid anchoring in the River Avon. Areas of prohibited anchorage within the area are clearly marked on Admiralty chart 1859. There are moorings in a number of the pills and creeks of the River Avon. Licenses and permissions are required from the relevant bodies prior to laying moorings.

When approaching and transiting the River Avon inbound, all vessels should keep a listening watch on VHF Channel 12. Inbound vessels over 30 metres, or carrying more than 12 passengers must report to Bristol VTS when at Shirehampton and Sea Mills reporting points.

Upon entering the River Avon (under the control of the Bristol Port Company) inform Avonmouth Signal Station that you are bound for the City Docks. If you are using VHF, call BRISTOL VTS on Channel 12, Low Power. Alternatively, signal International Code Alphabetical Flag R (by day).

Maximum speeds in the River Avon
Vessel drawingOvergroundThrough the water
Drawing 1.9m or more 7 knots 6 knots
Drawing less than 1.9m 9 knots 9 knots

If the red light is exhibited on the docking signal mast at Hotwells Pontoon, contact the Marine Services Supervisor on VHF Low Power Channel 14. Failing this, proceed along starboard side of river outside the main channel to the knuckle ladder at the Tongue Head, just upstream of the lock gates. Secure alongside this ladder and establish contact with the Marine Services Supervisor for docking instructions.If you are using VHF, contact the Marine Services Supervisor on Channel 14 'City Docks Radio' at Cumberland Basin when you have passed the Black Rock lights, and again when you reach the Hotwells Pontoon, for docking instructions.

When you are in the lock, keep to the outer end where the water will be less turbulent when the lock is being filled.

Vessels requiring a Junction Bridge swing or arriving on a stopgate tide and directed to wait in Cumberland Basin, may not be left unattended here without the Harbour Masters permission.

Small vessels entering Cumberland Basin are directed to the south side or north side to lay-by; vessles may not be left unattended here without the Marine Services Supervisors permission.

If you arrive at the Cumberland Basin entrance too late to be locked-in you have the following alternatives:

  • Go aground in soft mud alongside pontoons, but check with Avonmouth Signal Station VHF Channel 12.
  • Go aground on soft mud on North Wall, bow abreast ladder at No. 4 Survey Mark. Do not go closer to the channel than this.
  • Do not go aground abreast slipway between pontoons and Survey Mark 4 (obstructions).
  • Do not go aground on ladder by Survey Mark No. 2 (pilings obstructions).
  • Do not go aground on Tongue Head ladder just upstream of lockgates (pilings obstructions).

Sailing seaward

Vessels are strongly advised to give 24 hours notice of intention to leave the harbour or arrange locking out schedule with the docking staff on arrival during BST and must give 48 hours during GMT.

Harbour dues must be pre-paid before entering Entrance Lock.

If you have not paid your harbour dues or if you are seeking advice or information, secure at the wooden fendering at the south-west corner of the Cumberland Basin, go ashore and contact the Marine Services Supervisor at the Watch House or call the Marine Services Supervisor on VHF Channel 14 as you pass SS Great Britain and advise him of your required lock as per the Vessel Locking Schedule.

Mariners may phone the Coastguard Station from the Watch House free-of-charge, to advise them of passage plans and estimated time of arrival at destination.

When you are in the lock, secure your craft as described above.  However, turbulence should not be experienced when the lock is being emptied, and so be prepared to secure in any position as directed. Please ensure your ropes are clear on their cleats, will not jam, and are tended continuously. Mooring ropes should be at least 15m in length.

Sharpness passage and advice to small craft

Passage into the Severn by inland vessels should only be made by suitable vessels with experienced masters or pilots.

Navigational information on passages from Bristol Harbour

If you want to plan a journey into the Severn you should:

Sources of weather information

BBC Radio 4 - Shipping forecasts are broadcast for sea area Lundy (inshore - Lands End to St Davids Head).

Suggested websites: BBC weather or Maritime safety: weather and navigation on the web site.