The waters of North Wales can, in the right circumstances,
be quite delightful.
Working with the tides and wind leads to quick, comfortable passages, and sheltered, swell free, anchorages - with good food in uncrowded pubs. and restaurants.
The waters of North Wales can, in the right circumstances, be quite character forming. The strong tides and underwater contours can produce some interesting wind-over-tide effects. The good news is that, within the local cruising grounds (see illustration below), and particularly around Anglesey, there is always a weather shore.
Within the Menai Strait, there is always somewhere to find shelter and pleasant sailing, whatever the wind conditions. The notorious Swellies are completely benign at SLACK water - which does NOT coincide with High water. They exhibit virtually no sea in even storm force winds, but 8 knots of tide and numerous rocks make it prudent to get assistance for a first passage.
Apart from Conwy (with somewhat silted up marina, now protected by a cill), not a lot happens between Puffin Island and Point of Ayr. The Conwy entrance is a half-tide affair for most people, with about 3 knots of tide. Offshore banks break the force of strong north westerlies, but F5 from any direction can make for an interesting experience. East of Conwy, apart from Rhyl it's really `lunch only' stops as far as the River Dee - and for most people the next stop is Liverpool. Yet again, it must be approached at the right time of the tide, arriving at the Pierhead (near the Liver Buildings) about an hour before high water. This allows time to lock into Liverpool Marina. With 5 knot tides, it is, in fact, almost impossible to arrive at any other time!
Cruising from Holyhead
Get the cruising guide from the marina chandlery.
From Pwllheli in the south, with its marina and the (relatively) sheltered waters of Tremadog Bay to as far west as Bardsey Island, the waters are reasonably protected from the prevailing westerlies, but are subject to some interesting (in the Chinese curse sense) tides. Names such as the "Devils Tail" and "Hells Mouth" adequately describe the state of the water in other than calm conditions around Bardsey Island and 50 foot (15 metre) standing waves are not unknown in the Sound in a good blow! In some places, the underwater contours will create standing waves in a flat calm - but that's fun rather than dangerous!
From Bardsey Island, it is normally a run to Anglesey ahead of those south westerlies, with significant gusting around Bardsey Sound itself as a result of considerable down draughts from Braich-y-Pwll. Tides run at 4 - 6 knots just outside the Sound - and up to 8 knots (or more) in it. The route from the Sound to Anglesey trends away from the Welsh shore, with the majestic mountains (above and below the water!) of the Lleyn Peninsula, though it is worth a diversion into Porth Dinllaen (PY) to visit the pub on the beach.
As Caernarfon Bar is approached, sandbanks intrude, and extreme care must be taken not to fall foul of shoal waters extending from Dinas Dinlle to Llanddwyn Island.
Anyone crossing the Bar into the Menai Strait must enter through the buoyed channel during the three hours before High water. See "Cruising Anglesey" for the details. Landfall at other times is typically Llanddwyn Island close north of Caernarfon Bar. Whilst locals will cross Caernarfon Bar near HW in a strong breeze, it can be dangerous for the smaller boat or less experienced crew. A reach to Holyhead (giving South Stack a 5 - 7 nm offing in heavy weather) is to be preferred in heavier conditions. Better yet, pause in Porth Dinllaen until the wind abates or changes direction.