Moorings in Menai Strait and Anglesey

The Menai Strait is a tidal channel about 25 km long that separates Anglesey from the Gwynedd mainland, varying from about 400 metres wide to several kilometres. This coastal area also takes in the rest of Anglesey, including Holyhead, and the Conwy estuary to the east. The tide floods north-eastwards through the strait and then reverses, and between the Menai Suspension Bridge and the Britannia Bridge lie the Swellies, where rocks near the surface cause overfalls and whirlpools and spring streams reach nearly 5 knots. Slack water between the bridges comes roughly an hour before high or low water. Lavan Sands and the shifting banks off Caernarfon guard the two ends.

Several bodies look after the water. Caernarfon Harbour Trust is the statutory harbour authority from the Suspension Bridge to Caernarfon Bay, manages Victoria Dock Marina in Caernarfon and provides moorings in the River Seiont and at Port Dinorwic. Port Dinorwic, at Y Felinheli, also has a marina and boatyards. On the Anglesey shore, the county council licenses moorings at Menai Bridge, Glyn Garth, Beaumaris and Red Wharf Bay.

The Conwy estuary has swinging moorings as well as two marinas, Conwy Marina and Deganwy Marina, which both sit behind flap gates that can be crossed about three and a half hours either side of high water. Holyhead, on Holy Island, is a ferry port operated by Stena Line.

Moorings in the Menai Strait and Anglesey range from sill-controlled marina basins to swinging moorings in the strait and the Conwy estuary, and planning passages around the Swellies is part of keeping a boat here.