Tide times


Tidal Streams

Flood tide flows clockwise around Anglesey & Ebb flows anticlockwise.

The straits are a special case but well documented elsewhere.

The flood fills the straits from the Abermenai end. It briefly flows eastward throughout the whole strait before being met by the progressively strengthening flood entering from the Penmon end. This means that there is a section of slack water (where the tides meet) that moves  westwards until it reaches its westmost position at the swellies at between 2 and 1 hours before local high water. The straits continue to fill until local high water then start to empty, first from Abermenai and then from Penmon. This means that after a very brief time when the whole of the flow is Westwards, a section of slack water (where the tide is splitting east and west) moves westwards down the straits from Penmon, reaching Caernarfon about 5 hours after high water. The cycle then repeats!

Animation of tides

Downloadable sheet of the above GIF

Straits tides

Tidal stream graph1

Tide graph 2

Tide Graph 3

Slack water constants