Navigation in the harbour and bridge clearances

Areas of the harbour

The Floating Harbour is in the centre of the City of Bristol on the courses of the Rivers Avon and Frome.

30.94 hectares of water is impounded at a reasonably constant level behind lockgates at Cumberland Basin and between quay walls, some of which date from the 13th century.

Tall-masted vessels may proceed as far as Redcliffe Bridge, (subject to bridge movement and depth of water), the historic crossing point of the River Avon, some 2.5km from Cumberland Basin. Prince Street Swingbridge is passed on the way.

St Augustine’s Reach is an arm of the harbour constructed by the citizens of Bristol and Redcliffe between the years 1240 and 1247. Narrow Quay (formerly Bristol Quay) is on the starboard side of St Augustine’s Reach. At times of flood the River Frome discharges into the Harbour at this point. (At other times it discharges through Mylne’s Culvert to the diverted course of the River Avon known as the New Cut). The new bridge crossing St Augustine’s Reach was the subject of a public art competition. It is distinguishable by its two horns acting as counterweights. It was installed in 1998 and named Pero’s Bridge.

Beyond Prince Street Bridge on the port hand is the ‘Mud Dock’ built in 1625 by Robert Aldworth to provide a soft mud berth for shipping in the days before the Floating Harbour was created in 1809.

Halfway between Prince Street Bridge and Redcliffe Bridge, on the starboard hand, is Guinea Street Lock which leads through to Bathurst Basin where the Cabot Cruising Club’s moorings and headquarters vessel, ‘John Sebastian’ are situated.

The Feeder Canal connects the harbour (near Temple Meads Station) with the River Avon upstream of Netham Weir.

Tall-masted vessels may go as far up the Harbour as Redcliffe Bridge, (subject to bridge movement and depth of water) about 2.5km from Cumberland Basin.

St Augustine’s Reach is an arm of the harbour. Narrow Quay (formerly Bristol Quay) is on the starboard side of St Augustine’s Reach.

Beyond Prince Street Bridge on the port hand is the ‘Mud Dock’.

Halfway between Prince Street Bridge and Redcliffe Bridge, on the starboard hand, is Guinea Street Lock which leads through to Bathurst Basin where the Cabot Cruising Club’s moorings and headquarters vessel, 'John Sebastian' are situated.

Floating harbour navigation

The Floating Harbour and Feeder Canal are open for navigation by day and by night, although Netham Lock (see below) at the far end of the Feeder Canal is closed at night.

The charted depth of the Floating Harbour may be reduced through silting and therefore caution should be taken.

Navigation is subject to the ‘Collision Regulations’ and bye-laws made under the Bristol Docks Acts and any amendments. The whole of the City Docks should be regarded as a ‘Narrow Channel’.

Craft navigating after dusk must display an all-round white light.  Failure to do so is a safety risk and may result in a licence being revoked.

Vessels over 24 metres in length must inform the Harbour Office of their intentions to move within the Floating Harbour and obtain a harbour escort craft.

The speed limit in the Floating Harbour is 5.2 knots (6mph) and 3.5 knots (4mph) in the upper River Avon and Feeder Canal, unless special permission has been obtained from the Harbour Master.

Powered vessels should hold a steady course and slow speed when passing pleasurecraft moorings, sailing dinghies, canoes or rowing boats etc. As a general rule, a vessel should not be going so fast as to cause a breaking wave.

Mariners should be aware that the Harbour is used as a training area to teach newcomers in all watersports and extra caution is needed when passing these groups.

It should be assumed that two-way navigation applies through all bridgeways with the following exceptions:

  • Temple Meads Railway Arches - vessels should keep to the arch on the starboard side.
  • Plimsoll Bridge and Junction Lock Bridge when opened - vessels proceed in accordance with instructions from the Marine Services Supervisor or bridge operator.
  • Prince Street and Redcliffe Bridges - vessels proceeding upstream should give way to vessels proceeding downstream.
  • At bridges, locks and restricted areas.
  • Pero’s Bridge - vessels proceeding upstream using the central channel should give way to vessels proceeding downstream.

Attention is drawn to the risk of collision at the approaches to all bridgeways. Vessels should sound one prolonged blast before going through any bridgeways.

Yellow marker buoys are often used to denote an area being used for a special purpose and where ordinary navigation is regulated in accordance with a Notice to Mariners.

Dredgers display the signals prescribed in the ‘Collision Regulations’. Do not pass on the side of a dredging vessel on which is displayed two black balls or two red lights in vertical line. Vessels should proceed on the side of two green lights or two diamonds in vertical line.

Model boats are used in the Harbour and are required to keep clear of all other vessels. The white buoys, which are sometimes in use, have no significance to other vessels.

Netham Lock

It is essential to contact the the lock keeper on departure from either Hanham or the Floating Harbour to establish the tidal river and locking conditions, on Bristol 0117 977 6590.

Vessels must arrive at the Netham Lock, at least one hour before the lock keeper goes off duty to ensure passage through the lock.

The Feeder Canal takes water from the River Avon to the Floating Harbour. It also serves as a navigation link between the Floating Harbour and the upstream navigation towards the city of Bath via Netham Lock.

During the day the lockgates at Netham Lock will be opened unless the water level in the river between Netham and Hanham is above or below the level of the harbour. Outside of these times, it may be possible to navigate from Cumberland Basin to Hanham Lock (a distance of 11.2km) on the level. The speed limit in the Feeder Canal and River Avon above Netham Weir is 4mph.

Important - strong currents near Netham Lock

Vessels entering the Floating Harbour through Netham Lock account for possible strong currents. Great care should be taken when navigating this area. If necessary, vessels should hold off in Totterdown Basin and assess the flow before passing through Old Totterdown Lock.

Maximum sizes of vessels

The maximum sizes of vessels which can use Feeder Canal and Netham Lock are:

  • Length Overall - 24.4 metres
  • Beam - 5.4 metres
  • Draught -1.9 metres
  • Height from waterline - 3.1 metres

See the relevant Local Notice to Mariners for summer and winter staffing times of Netham Lock.

Safety information

Take special note of this information regarding safety on the Tidal River Avon, Netham Lock and Netham Weir, and old Totterdown Lock.

On tides of 9.6m and over, the lockgates at Netham Lock are closed to exclude the tidal water which flows over Netham Weir, and for a period of about three-and-a-half hours vessels have to lock through.

When the level of water in the river is raised (either by tide or fresh water flow) there is an increased risk of vessels being carried over Netham Weir. Because of this danger, care should be exercised when navigating the river under these conditions. Your craft will need a reliable engine and be capable of cruising at five knots to make adequate headway against currents of about two-and-a-half knots.

A proper anchor and warp (properly secured) are essential. Vessels of the maximum height (3.1m) will not be able to get under Netham Bridge with an adequate margin if the river level is more than 0.75m above harbour datum (the level of the crest of Netham Weir), corresponding to a 9.45m tide at Cumberland Basin.

Bridge operations

Prince Street Swing Bridge

Prince Street Bridge swings are normally limited to no more than one per hour. It operates between these times:

Summer: 09.30 - 21.30

Winter: 09.30 - 16.15

For the actual seasonal swing times, and booking procedures, consult the Local Notice to Mariners or contact the Harbour Office.

The water level is usually between 0.0m and 0.1m above harbour datum, but can be up to 0.5m above. Always check the gauge boards, which are on bridge abutments, before passing under the bridge.

Redcliffe and Pero's Bascule Bridges

Prior arrangement for the raising of Pero’s bascule bridge should be made with the Harbour Office.

Bridge clearances

Bridge clearance above normal level (6.10 metres above O.D. Newlyn)

The clearances apply when the water level in the Floating Harbour is at Normal Float Level. Variations of maximum 0.5 metres either way are not uncommon.

Bridge Clearance / metres Bridge type
Plimsoll Bridge 5.8 metres
But varies from 5.8 metres at the south side to 6.7 metres at the north side of the lock. Reduced on the spring tides - by 0.8 metres on the top of a M.H.W.S. tide.
Junction Lock Bridge 2.5 metres Swing
Prince Street Bridge 2.2 metres Swing
Peros Bridge - Centre pan
- East + West pan
3.3 metres
2.2 metres for a distance of 6 metres from bridge piers.
Guinea Street Bridge 2.7 metres Swing
Redcliffe Bridge (do not use East and West arches) 3.6 metres Bascule
Bristol Bridge - centre arch (do not use East arch) 4.1 metres Fixed
St. Phillips Bridge 4.2 metres Fixed
Temple Way Bridge 4.4 metres Fixed
Temple Foot Bridge 3.3 metres Fixed
Railway Arches (north side) 5.4 metres Fixed
Avon Street Bridge 3.3 metres Fixed
Silverthorne Lane Footbridge 3.8 metres Fixed
Services Bridge (1) 7.4 metres Fixed
Services Bridge (2) 6.6 metres Fixed
Feeder Road Skew Bridge (railway) 6.7 metres Fixed
Marsh Lane Bridge 3.8 metres Fixed
Netham Bridge 3.9 metres Fixed
Netham Bailey Bridge 4.0 metres Fixed
St. Annes Footbridge
(above O.D. Newlyn)
12.8 metres Fixed
Bickley Wood Road Bridge
(above O.D. Newlyn)
27 metres Fixed
Netham Dam top
(above Cumberland cill)
9.45 metres  
Netham Dam bottom (above O.D. Newlyn) 6.104 metres