You guide your boat through the thick San Francisco fog. You set a compass course and listen for the fog horns on the Golden Gate bridge, which you never see as you pass beneath. You stay to the south to avoid commercial traffic. When you hear the sound of automobiles above, you know you are under the bridge. Then you head into the bay, veering starboard to avoid the rocks of Alcatraz. Soon you are at City Front, safely out of the fog.

Whew.

Those were the days before global positioning satellite (GPS) equipment. Today, GPS can pinpoint your location so precisely that boaters say you can tell if your anchor is dragging on the bottom. Linked to your autopilot, GPS corrects for the unseen influences of wind and current, becoming a reliable helmsman that directs you safely to the city front.

GPS, plotters, and on-board radar provide today's boaters with a greater level of security than ever before. Better yet, the GPS that cost $1200 five years ago costs in the $200 range now.

But GPS is just one of a number of technological advances that are within reach of all serious boaters. Some of this progress you might expect, such as cleaner, more efficient engines. But email and the Internet?

Yes. Using HF radio you can send and receive email on the high seas. The speed won't blind you, though. Expect transfer rates of only 10 to 140 characters per second, according to Stan Honey, director and founder of the SailMail Association in Palo Alto, California. That's the equivalent of modem speeds from the 1980s. This is "stunningly slow by modern standards," Honey says, but "once they get used to the convenience of email for arranging visits, ordering parts, and updating friends and relatives," many cruisers "would never do without (email) again."

With a range of 7000 miles from Palo Alto, the SailMail Association has members from Central America to Alaska, and across the South Pacific. While Sail Mail does reach the east coast, Honey says that users who plan to stay there might be better served by Globe Wireless, Pinoak, or the Ham radio networks. Honey plans to add an east coast station later this year. Eventually, he expects the speed of boat-based email to increase, although that depends on the FCC allocating wider bandwidth for the purpose.

So where does that leave surfing the Internet? Well...in the same boat.

To learn about accessing the World Wide Web at sea, look at ATOLWEB. Mind you, this isn't your children's Internet, replete with music and blazing graphics. But Arretec, the U.K.-based creator of ATOLWEB, claims that you get what is important: the content. The trick, they say, is to reduce file sizes and strip away all of the unessential parts of the web page. Then your page arrives by email, with only the text and web links remaining.

Even with text only, poor radio propagation can mean up to an hour to download a 10 kilobyte file, Arretec says. At this rate, forget about emailing photos of your latest port of call.

Internet by email works for any page in the world, giving the boater access to weather forecasts, search engines, and much more. ATOLWEB itself is free, although you still may have to pay for using a commercial radio email service. For example, using SailMail costs $200 per vessel per year.

High tech on the high seas is a major advance, but what about the engines that get you out to sea in the first place?

Today's engines are lighter and more powerful than ever before, with the ability to run hotter, cleaner, and more efficiently. These cleaner engines result in less pollution, less damage to wildlife, and reduced oil smell -- in general, they are kinder to the environment.

One of the forces propelling engine technology is the state of California, with its strict emission laws. Outboard engines will be going to four-cycle and computer-controlled ignitions and fuel injection. Companies such as Mercury (for outboards) and Caterpillar (for diesels) take advantage of the technology to produce a wide range of engines for every size boat up to large trawlers and cruisers. Prices can range from $5,000 to $15,000 plus installation, making engines mainly "new boat" items.

So now you're headed to San Diego with dozens of dolphins frolicking in your bow wave. You know that engine pollutants won't spoil their fun or ruin their health. And as the dolphins finish their play, your GPS tells you that you're due west of Big Sur. So how soon can you tell the folks back home?

You can do it right now. Just send them an email.