Lock Information


The Lock has the following dimensions:

  • Width 12 metres
  • Length 44 metres
  • Height of outer cill: 1.5 metres below chart datum
  • Height of inner cill: 0.5 metres below chart datum

To download the latest Lock Freeflow Guide please click here.

Before approaching the Harbour please call the Lock Tower on VHF Channel 12 for clearance, and obey both the traffic lights and the directions of the Lock Keeper.

All boat movements are controlled by traffic lights displayed from masts at both ends of the Lock.  These lights are arranged vertically and have the following meanings:

3 vertical fixed red light:      Lock closed or in use - do not proceed

3 vertical fixed green light:  proceed into the Lock

Please follow the procedure below:

  • Call the Lock Tower or VHF Channel 12 (call sign "Sutton Lock") and await further instructions.  Please keep well clear of the Lock Gates in case of exiting traffic and maintain a listening watch on VHF Channel 12 at all times.
  • Fix suitable fenders and warps.
  • Do not enter the Lock until three vertical green lights are displayed and you are instructed to do so by the Lock Keeper.  Enter at dead slow speed and moor where directed.
  • All vessels should be secured with fore and aft ropes and springs where necessary.
  • Please do not leave your vessel during the lock cycle. The ladders are for use by staff and for emergency use only.
  • When the Lock cycle is completed please wait until the gates are fully opened and any tidal movement has died down before releasing your lines and leaving the Lock.

Please exit only when instructed to do so by the Lock Keeper.