Tides and Weather

Tide times and heights are of great importance to divers, wherever you dive around the coast of the UK.  Wherever you are high and low tides occur twice a day, at about 12 hour intervals.  

Spring Tides occur roughly every 16 days near to a Full Moon and New Moon when the tide-raising forces of the Sun and Moon are at a maximum.

Neap Tides occur roughly every 16 days near the Moon’s first and last quarters when the tide-raising forces of Sun and Moon are at a minimum. 

Click here for Frequently Asked Questions on How Tides Work

Best time for diving at Porthkerris
The best time to dive on the Manacles and surrounding area is on Neap Tides, this is when the movement of water is least so you will get less tide on the dive sites.  Slack water, which is the period of time before the tide turns, so when tidal movement is likely to be least, is approximately 1 hour after High and Low water at Falmouth.  Drawna Rock can be dived at any state of the tide but make sure you know what the tide is doing and how strong it is so you can determine the best direction to dive it.  Slack water in the Manacles area is normally 1 hour after high water at Falmouth.

We will be happy to send you a copy of an up-to-date tide table, simply send us a Stamped Addressed Envelope and we will be happy to post one out by return.

Weather
Just as tides are important to divers so is the weather.  The wind will affect any dive site and the entry/exit conditions if you are diving from the shore.  It is very important to make sure you have an up-to-date weather forecast before you leave home especially if you have to travel some distance to the dive site. 

The only weather that stops us from launching boats or diving from the shore at Porthkerris is any wind with the direction of “East” in it, e.g E, NE, SE.  However, if you are in any doubt as to the conditions at Porthkerris give us a call, as conditions may be slightly different to what the forecast actually says.

The cove, with Drawna Rocks standing off, nestles under high cliffs and is protected from all but Easterly Winds, therefore, in the summer, when the prevailing winds are occasionally very strong from the south west, Porthkerris is generally flat calm. 

The source of professional weather information is the Met Office who are located at Exeter but it is also possible to get forecasts from: 

• National and local radio stations
• Telephone recordings
• Mobile text messages
• The Internet
• Local Press
• Television
• Local Coastguard station

You are always welcome to call us at Porthkerris to get information on the latest conditions in the area before you dive.