The Menai Strait and surrounding waters are some of the most challenging for passage planning. Local sailor Don Smith describes how to work the tides
My neighbour’s boat, Inthral, is berthed in Victoria Dock, Caernarfon, where she had been surveyed after a poor deck repair by a firm no longer trading. The surveyor made his recommendations very clear, “Get it done by Yacht Systems in Deganwy.”
As my boat is berthed in Conwy Marina, his first question for me was, could he get from Caernarfon to Conwy on the same tide? Yes, all the crucial tidal gates are open as you reach them, assuming a boat speed of about 5kts. However, getting back on a single tide, in a displacement vessel, is not so easy. Tidal gates ahead of you close, eg the Swellies, or have not yet reopened, eg Victoria Dock.” In a fast RIB, it’s not a problem, but...
In short, Conwy bound, leave Caernarfon’s Victoria Dock as soon as the gate opens, transit the Swellies before high water slack (Liverpool HW-2) and ride the eastbound flood tide for as long as you can up the Menai Strait. You can use the Puffin sound and go round the island before heading for the Conwy fairway but the Penmean Swatch is shorter.
You should reach the Penmean Swatch before the westbound flood tide gathers too much way at about an hour before local high water and be out of most of the tide that runs along the Anglesey shore as you cross the Penmaen Swatch.
Setting out
We made the delivery trip in mid-August when Liverpool HW was 1709, leaving Victoria Dock at 1323 as soon as the gate opened, bound for Deganwy Marina with a crew of skipper plus three. Motoring at 5kts, making 7.5kts over the ground, we were doing well so we didn’t make any sail to capture the following wind – southwesterly 10-15kts. We were well ahead of the game and arrived at Stephenson’s Britannia Bridge before Liverpool HW-2.5, still with a strong eastbound flood tide, and shot the mainland span of Britannia Bridge, round Price’s Point and out under the Telford’s Menai Suspension Bridge, still carrying the tide.
Transiting the Swellies eastbound before local high-water slack hadn’t been a problem; there was no significant turbulence or sheers though a short trail of disturbed water marked the head of Cribbin reef. We pressed on and reached Beaumaris before meeting the local slack water as it advanced up the strait towards the Swellies b
