Silloth pier slipway

The Solway Firth has the second greatest tidal range in the UK after the Severn Estuary, with a mean spring range of about 8.4 metres at Silloth and tidal streams reaching about 4 knots at springs and 2 knots at neaps. Its inner reaches are dominated by extensive intertidal sand and mudflats and shifting, unmarked sandbanks that dry out at low water and reshape the firth daily; high water at Annan, on the Scottish shore opposite, occurs about an hour after high water at Maryport to the south.

The firth here lies within the Solway Firth Special Protection Area and Special Area of Conservation, and the intertidal flats and saltmarsh form part of the Upper Solway Flats and Marshes Ramsar site and SSSI, among the largest continuous areas of intertidal habitat in Britain after Morecambe Bay and the Wash. The site regularly supports over 130,000 wintering waterfowl, and more than a tenth of Britain's natterjack toad population lives along this shore, its most northerly outpost in the country. The dune and beach frontage immediately south of the town carries a separate designation, the Silloth Dunes and Mawbray Bank SSSI.

East Cote lighthouse, rebuilt by the harbour authority in 1997, stands on the promenade between Silloth and Skinburness and is the most northerly lighthouse on England's west coast; offshore to the south-west, the pile-legged Lees Scar lighthouse marks a submerged reef known locally as "Tommy Legs". Grune Point, where the coast path turns south towards Skinburness and Allonby, forms the peninsula tip north-east of the launch.