21 Aug 2009

ELWS: the lowest low water I have ever seen.

I can't ever remember seeing this much beach exposed at low tide. ELWS means 'extreme low water springs', the datum at which low tide is fixed on maritime charts.

1 comment:

lifeboatjohn said...

Sorry to be a smart arse Peter but tides on UKHO charts (and most others internationally) are measured from a chart datum which is based on the lowest astronomical tide or LAT for short.

This means that all tidal heights can then be positive. However, in practise it is possible for tides to be lower than LAT due to meteorlogical factors such as strong winds from a certain direction (southerly in Runswick) and very high air pressures.

The differences in practise are small but sometimes important!

By the way, I enjoyed the pictures...it's a long time since I've seen the bay so dry.