Computers and salt water don't mix. But PCs are just the thing for old salts, who are taking laptops to sea in ever greater numbers, according to experts at last week's London Boat Show. "A lot of people are now using PCs for navigation, chart-reading and looking up satellite weather maps," says Brian Ash, managing director of Manstbrite Marine Electronics, British distributor for the new sub-pounds 1,400 Interphase PC/ View scanning sonar system.
Despite their specialisation, Ash says dedicated sonar displays sell best to leisure sailors. Now it will be yet another function that can be accessed better from a PC display, especially in colour. "When you're looking at a sonar target in colour, the colour echoes you are getting back represent the strength of the signal coming back [and its solidity], making it easier to identify what you are looking at [such as a shoal of fish, a wreck or a rock]," he explains.
But the PC's biggest attraction for Britain's 2.5 million boat owners is how simple it makes navigation. Thanks to Global Positioning System satellites and electronic charts, even the most inept sailors now have no excuse for getting lost.
PC navigation systems can cost as little as pounds 500 for a DOS-based system from PC Plotter, using basic charts (pounds 100 for the whole south coast) and a second-hand laptop. Its new Windows 95 software costs pounds 250 and uses more expensive, detailed Navionics charts (pounds 199 for the central Channel area).
Glen Challis, PC Plotter's managing director, recommends users buy second- hand laptops. "If you spend pounds 2,000 on a new computer, the last thing you want to do is take it aboard, unless you've lots of money."
He sources adequate Pentium 166MHz models from a dealer for pounds 1,000 or less, but can supply a new, waterproof, "seaworthy" version for pounds 2,500. "The ordinary laptops we've always used on board have never broken. They are not built to do it, but if they are kept carefully, perhaps in foam, they can do it," he says.
There are lots of dedicated navigation systems available, but Anne Edmonds, marketing manager for PC Maritime, says people are moving to PC-based systems because they are so flexible, they are easily upgraded and they cost less to run, as you can usually shop around for different makes of chart. Its new pounds 399 Navmaster 3.0 is being used by Shell for its tankers. As GPS and chart data don't always match, it intelligently corrects for differences, and can continue on "dead reckoning" if GPS fails.
One of the most helpful of the new navigation systems is Tsunamis (pounds 795 including 40 charts), from Transas Dataco, which calculates the state of the tides, so you can see when not to enter restricted waters such as estuaries. They are more expensive than the rest of the Transas range, but Transas's Linda Broomfield says: "Most people seem to want to spend the money."
With so much information, the screen can be confusing, especially on a small laptop display. But Tsunamis, along with most of its rivals, uses vector charts built from layers of information, so it can show simplified views containing only the data you need. There are two chart types: raster, used by the Admiralty Raster Charts Service, which are exact scanned copies of paper charts; and vector charts, which hold each item of data separately, giving it a wider range of scales.
Vector charts also take up less disk space. "More than 9,000 charts, covering the whole of the world, will fit in 900Mb of hard disk, whereas raster charts are about 3Mb each," says Gillian Lovegrove, director of Chartwork, which uses C-Map charts for its new pounds 395 Win Chart Pro Plus system. Most users will need charts only for whichever part of the UK coastal waters they sail, at anything from pounds 10 to pounds 30 each (down to about pounds 4 each if bought in bulk).
Fortunately this does not mean boat-owners have to run to the chandlers each time they sail new waters. A CD-Rom stores all the charts, and authorisation codes to use them can be purchased by phone. Further information, such as locations of wrecks or good waterside pubs, is easily added using standard drawing tools and a database in Win Chart Pro Plus. For small boats, Lovegrove's ideal solution is a GPS receiver, software and a tiny Toshiba Libretto laptop for pounds 1,995.
But Alan Cherry, a member of the Royal Institute of Navigation, is dismissive of PC use, saying that the people using them either already had laptop PCs or cannot resist toys - "and they're not really making very much use of them".
He believes the chart displays aren't yet good enough. "You've got to get used to operating on an A4-sized chart or smaller," he says. Although the Navy is "going for them in a big way", their emphasis is on big as they can project them on to large plotting tables. Maps are also more romantic. Although Cherry uses a PC at home, he says there is something magical about paper charts.
There is also something magical about winning, and racing is where traditional sailing skills are really put to the test - PC against PC. While a keen eye and quick reactions are useful, so are systems such as Tactician 2000, from Brookes and Gatehouse. It can help racers push their boats to the limit, tracking boat and wind speed/direction, and providing navigation calculations. It also allows users to display "virtual instruments" anywhere on the boat using LCD panels, so everyone knows what's happening.
After the race, it shows if you maximised your performance against the elements and competition, so you can spot weaknesses and correct them in the next race. It can even control the auto-pilot, handy for long races.
The Windows 95 software costs pounds 650, but you also have to have B&G's Hercules 5000 instrument system, which costs at least pounds 5,000.
You can hone your sailing skills out of the water with PC Maritime's good-looking Match Racing 2000, the more challenging Laser Match Racing, or its wide range of training programs, including new radar and weather courses. You can also buy simulation and training software from the Royal Yachting Association Web site, which is full of information on sailing.
For more excitement, Interplay's noisy new VR Sports Powerboat Racing for PC and Sony PlayStation was launched at the show. Some sequences seem like Bond movies, with jumping across roads and roaring between converging tankers ready to tear the boat apart. Otherwise it's fairly realistic and the courses, including an English backwater, New York and the Grand Canyon, look good.
You don't, of course, need your own boat to sail. But if you want to book a sailing holiday, you can now explore the options on your Mac or PC using a CD-Rom interactive brochure launched at the show by Sunworld Sailing. Most of the other holiday companies are also on the Web.
Admiralty Raster Charts Service
Brookes and Gatehouse
Royal Yachting Association