How to work out tidal height calculation

Sticky forms tidal height calculation

If you’re looking for the forms referred to in the October 2016 issue of PBO download them here.

PBO contributor Sticky Stapylton has compiled a handy guide to working out tidal heights for standard and secondary ports.

Standard ports are those where the tides have been checked and records made over many years.

Secondary ports are those that are of less importance, for which the tides can be worked out using standard port data.

Sticky says: ‘Assuming your charts have been updated from the appropriate Notices to Mariners websites, the major concern when entering a river, estuary or harbour is that although you have a date on your chart, you may not know how current the latest survey is, you do not know when the area was last dredged, and you will only be able to make a rough guess as to how much high or low pressure weather systems will affect your height of tide.

‘The essential principle is that you must add a buffer in the way of time and of height in order to be safe: I also always try to avoid entering a port on a falling tide.

‘There are many electronic programmes that will give you an idea of the rise of tide, but be aware there are going to be differences in the answers you achieve.’

Find the full article and a step-by-step guide in the March 2014 issue of Practical Boat Owner magazine. Browse the online copy service to browse for more archived articles.