Tides & Flows

This note explains in some detail how the tides work on the River Trent. If you prefer, you can download the PDF using the link at the foot of this page.


Links to the various flow and level gauges on the river are included here.

Tides – Departure planning

Disclaimer: All Information on the Group is given in good faith but is used entirely at your own risk.

Last updated: 6th March 2022

This document is prepared for low power vessels including most narrowboats. It is not expected such craft, especially if new to the area, will progress on the river north of Keadby.

It is NOT strictly necessary for a visiting boater to do this calculation as the lock keepers have been a traditional source of this information and continue to be so. But this information may be of use for forward planning.

Calculating times of tide at any Trent Lock on to tidal river

All tide times on the river are based on the predicted times of high water (HW) at Hull (Albert Dock) Tide Times. This link will provide tide data for the next 7 days. If planning beyond 7 days, the information may be purchased at this web site (in PDF form or in a nice printed booklet), or elsewhere.

On the following pages, select the lock you are departing and enter the appropriate HW (Albert Dock) in the yellow boxes. If travelling between the last Sunday in March and the last Sunday in October, sure the time of high tide is in British Summer Time not GMT.

The simple calculation will then give you the APPROXIMATE time a “Low Powered” boat would be expected to leave any of the Trent’s four tidal river locks. However, it should be anticipated that a more accurate time will be obtained from the lock keeper who should be consulted 24 to 48 hours prior to your arrival at the lock. The lock keeper will consider the local conditions on the day such as:

  1. the nature of the tide (Springs or Neaps);
  2. the amount of water in the river (the “Fresh”), and;
  3. any restrictions at their lock, and the lock you are heading for, eg operating hours are normally 0700-1900.

On the day it is not unusual for climatic conditions to significantly delay or advance the tide time, so it is as well to plan to arrive a couple of hours before your departure time.

Torksey Lock has substantial visitor moorings on the river side of the lock which can be used if “in transit”. The lock also has a high sill which can only be crossed at or close to high water, so arrangements for entry to the Fossdyke, or departure from it, must be agreed with the lock keeper and any delay allowed for in your planning.

1: Departing Cromwell Lock

Depart on the ebb tide but early enough to allow approx. 3 hours to get to Torksey before flood tide starts at Torksey:

It is usual for low power craft heading for West Stockwith or Keadby to break their voyage at Torksey visitor moorings (16 miles) to allow the rising flood tide to pass. This is usually an overnight stop. Other options might be discussed with the lock keeper.

2: Departing Torksey Lock

2A: For Departures to West Stockwith (14 miles) and Keadby (27 miles)

Depart from the visitor mooring below the lock approximately 1 hour before the ebb starts at Torksey (You will initially push into the last of the incoming tide for about 45 mins)

2B: For Departures to Cromwell (16 miles)

Depart from the visitor moorings below the lock on the flood tide.

On weak tides with little “Fresh” the Lock Keeper may advise a larger window of opportunity for this passage as the ebb tide is relatively weak towards Cromwell. This may allow a vessel to pass through the lock immediately before departure to Cromwell.

3. Departing West Stockwith Lock

3A. For Departures to Keadby (13 miles)

Depart on the ebb tide. You will usually arrive at Keadby while the ebb is still flowing and need to stem the tide to enter Keadby lock.

3B For Departures to Torksey (14 miles) and Cromwell (30 miles)

Depart on the first of the flood.

For ease, the Lock keeper will often compare the HW Hull time to be the same as LW West Stockwith.

Boats heading for Cromwell will usually leave first, and may lose the following tide before arrival at Cromwell, but tides in this last section of river before Cromwell are usually reasonably easy to punch into.

4. Departure From Keadby Lock

4A. For Departures to West Stockwith (13 miles)
Leave about 1 hour after Keadby Flood starts, the objective is to arrive at West Stockwith at slack water.

4B. For Departures to Torksey (27 miles) and Cromwell (43 miles)
Leave as early as possible on the flood tide.

Moorings KM Marker
Cromwell Lock – Moorings above and below lock46/47
Marham Boat Club (Private)62
Dunham CRT 48hr65
Laneham Ski Club (Private)68
Torksey Lock Visitor Moorings72
Gainsborough Pontoon*88+

    *Below the Gainsborough bridge the Navigation becomes the responsibility of the Humber Port Authority, and no further Km Markers are in place.

    *IMPORTANT: Gainsborough Pontoon dries out on some low waters when “Fresh” levels are low, especially at the ends of the jetty. The use of this jetty should be discussed with the Lock Keepers if staying through a low water.

    Boats moored here on the first of the flood are also liable to be exposed to the “Aegre” if Hull HW approaches 8m or above.