After passing Aberdovey and Barmouth, in Cardigan Bay, we sighted Saint Tudwell's Island; and then rounding Bardsey Island, on which stands a square white tower, ninety-nine feet in height, with one bright fixed light shining far out over Saint George's Channel, we ran north past Porthdinlleyn, steering for Caernarvon, at the southern entrance of the Menai Straits.