Down river of Shardlow, the non-tidal river is navigable as far as the Cromwell Lock near Newark, except in Nottingham (Beeston Cut & Nottingham Canal) and just west of Nottingham, where there are two lengths of canal, Sawley and Cranfleet cuts. Below Cromwell lock, the Trent is tidal, and therefore only navigable by experienced, well-equipped boaters. Navigation lights and a proper anchor and cable are compulsory. Associated British Ports, the navigation authority for the river from Gainsborough to Trent Falls, insist that anyone in charge of a boat must be experienced at navigating in tidal waters.