I prefer to navigate my dinghy by looking at the banks or coasts as I sail along, for simplicity it has those GPS things beat by a long way. I have a compass in the boat, but hardly ever use it. I also have charts, but they stay at home as the information on them is mostly irrelevant to a boat drawing less than a foot, and they go blank just when the rivers start to get interesting in their upper reaches. Pilot books are nice to look at and dream over, as Peter Bick said in his recent review of one, but they seldom tell you anything that you cannot read on a map or chart. And they are terribly gloomy about things like crossing bars and rounding headlands, enough to make you wonder whether to go out in your boat at all.

So when it comes to finding out what this land looks like that I navigate by, there is nothing to beat an Ordnance Survey Map. There are two scales that serve for this. There is the magenta backed 1:50,000 (1¼”:1M) Landranger Series. Each map depicts an area of 40km x 40km (25M x 25M) and costs £5.25. So 14 maps take you from Land’s End along the south coast to North Foreland. But the scale is just too small to give as much detail as I like, particularly in the intricate bits up the creeks. (Their predecessors, the now obsolete 1 inch:1 mile maps are just as good and often available second-hand.)

The runaway preferred choice is the 1:25,000 (2½”:1M) maps. Unlike the Landranger which covers the whole country in a uniform series, the 1:25,000 is rather more complicated. At the present time (beginning of 1999) you will find that the country is covered by three different types. There are the yellow backed Outdoor Leisure Maps which are confined to the principal tourist areas, including such dinghy cruising waters as — South Devon, Poole Harbour, The Solent, Lake District and The Norfolk Broads. These maps, in their latest editions each depict an area of 30km x 20km (18¾M x 12½M) and are printed on both sides of the sheet. At £6.50 they are reasonable value.

Filling the gaps between these, so to speak, which is most of the country in fact, will be the orange backed Explorer Series. These are at the same scale as the OLM and either depict the same area, or two thirds of it (20km x 20km) and sell at £5.50 so are usually even better value. At the present time however these maps only cover the south of the country — roughly London to mid Wales with a strip up to the Wash. But it is intended that the whole of Great Britain will be included in the series in the course of the next six years.

The rest of the country, not yet covered yet by either of these, is at present covered by the obsolescent green backed Pathfinder Series, which only depict an area of 20km x 10km, and a few of half that size. Selling at £4.50p, they are not good value compared to the others. The standard of mapping is however just as good, except that they lack a few items of tourist information, which is no great loss. County Maps & Minerals, 22 River Street, Truro, Cornwall, TR1 2SJ — 01872 272972 — offers any of these maps encapsulated and thus rendered completely waterproof at an extra charge of approximately £5.50 each. This may be more convenient, if more expensive, than trying to stuff them into those map cases used by walkers. You may also find this service available elsewhere.

There is a one kilometre grid on the maps and the margins also show latitude and longitude (and therefore nautical miles on the vertical margin). There is a kilometre and land mile scale on the bottom edge and a foot-metre scale. The quality of mapping at this scale is excellent on all these maps. Among the, perhaps over-generous, scattering of tourist information symbols can be found: launching slipways, public houses and public conveniences, all of particular interest to DCA members. And on the coasts are shown: cliffs, woods, scree, field boundaries, piers, groins and shore based beacons.

The water however is plain blue without submarine contours, and only a very few fixed off-shore beacons are shown. But as one can take a dinghy almost anywhere that does not dry out at low tide, this is seldom a problem, and the navigation marks can be ‘read’ as you come to them. There are exceptions of course, for example, the submarine barrier between Southsea and Horse Sand Fort in the Solent is not marked at all. But this illustrates that reliance on any one system is dangerous. This and any other omissions can be plotted on to the map from a chart. Even the Ordnance Survey suffers an occasional lapse as well. My recently bought Isle of Wight map, claimed to be revised to 1998, did not show that the beach at Beaulieu River entrance had been built up to block the channel known as the Bull Run, though this was done ten years ago.

The land between mean high and mean low tide is remarkably well mapped, along the coast as well as in the rivers and creeks, and it is this area that is of particular use to DCA ditch crawlers. Rocks, sand, shingle and mud are separately depicted, and even the little runnels in the creeks seem to be correctly plotted. One misses the fact that drying heights are not shown, but it is not such a serious handicap as tidal information is perhaps better worked out in advance, and entered in a note-book if one cannot remember it. Have a look in your local map shop and see if these maps will suit you for finding your way around your cruising ground.