Wednesday 23rd November

John Barry

The How and Why of Tides


The tides have a major effect on our time on the water – and have a seemingly infinite variability around the world. Have you ever asked yourself questions about why they happen and how are they predicted?  How accurate are the tide tables?  And what about tidal streams?

This talk will explain the fundamental forces involved, how they're analysed and modelled to create predictions, and how the tidal characteristics change  locally and around the world. This is all mixed in with who discovered what and why the usual explanations published for day skippers and yacht masters about tidal theory are so misleading, or just downright wrong.  

From Ungava bay to Lowestoft, from Venice to Port Circumcision, from Galileo to Dr Doodson, here is a description of how and why tides happen, how predictions are generated, and some of the other effects that we need to look out for.