2.9 Pilots and guidebooks

Tidal diamonds and detailed tidal atlases are not available for all areas. Often, we must rely on less complete data given in narrative form from local experts. Such data can be found in sailing directions, books that are written to convey local knowledge to mariners. These are colloquially know as ‘pilots’. The UKHO publishes a range of pilots covering the UK in detail and the rest of the world in less detail. Other national agencies do the same. The information in these pilots is primarily intended for large ships, so yachtsman have produced their own pilots, often with more detailed information, for areas in which they cruise. These are often useful for kayakers.

Sea kayaking guidebooks include the most important tidal information from pilots and other sources. Being focused on kayaks, rather than large ships or yachts, they’re a great source of information in a compact format. Over the last few year, Pesda Press has published an excellent set of guidebooks covering most of the UK. For most kayakers, these books will be cheaper, more accessible and better than UKHO or yachting pilots.

3 options for tidal information for the Isles of Scilly. From left to right – the UKHO (Admiralty) pilot for the English Channel, the Imray (yachtsman’s) pilot for the Scillies and the Pesda Press sea kayak guide to SW England. Being focussed on big ships and covering a huge area, the Admiralty Pilot is almost useless in this area (and is expensive). The Imray pilot has a wealth of detailed information, but is costly for the small area it covers. The sea kayaker’s guide is a great compromise – it’s good value for the area covered, has appropriate detail for most kayakers’ needs, has less extraneous information and is very user friendly.

All pilots use a similar format for describing tidal streams. In sea kayak pilots you will also see tidal stream data shown graphically on maps:

Example of tidal stream information. The Pesda Press series of guidebooks use a very similar format

Pilot information is presented in a fairly understandable format. Its use is best illustrated by an example.

Describe the tidal flow in Saint Mary’s Sound on June 14th 2017 (HW Plymouth is at 09:29 BST and 21:44 BST)?

We already know that HW Plymouth is at 09:29 BST and 21:44 BST.

The ESE stream begins HW Plymouth -5:00
09:29 – 05:00 = 04:29 BST
21:44 – 05:00 = 16:44 BST

The WNW stream begins HW Plymouth +2:00
09:29 + 02:00 = 11:29 BST
21:44 + 02:00 = 23:44 BST

So, we expect the tide to run ESE in the morning (from 04:29), turning WNW at 11:29. It turns ESE again at 16:44, running in this direction until 23:44.