Among Chesapeake sailors, waterlust has cured cabin fever, and boat-buying time is here. Fancy brochures show sloops slicing through the water, mermaids sunning on the foredeck, a crew grinning at the skipper. The brockures invariably end: "Sail-Away Price $ - - - ."

Caveat emptor .

"Sail-away" prices are to sailboats what "sticker prices" are to cars -- with one big exception. You can pay sticker price for a new automobile, drive it to the nearest inspection station and leave with a steam of approval. Not so with sailboats.

You can pay a sailboat's "sail-away" price, tack smartly onto the Bay and run afoul, seriously afoul, of the U.S. Coast Guard. Why? No anchor, no life preservers, no harn, whistle or bell to avoid collisions; none has been furnished by the builder. As a result, your vessel can't pass the Coast Guard's standard safety inspection for want of required equipment.

The same holds true for most production sailboats, which means that in all but the balmiest weather they're unsafe at sea.

This sweeping, perhaps controversial generalization is based on 30 years' sailing EXPERIENCE BACKSTOPPED BY INTERVIEWS WITH YACHT BROKERS, MARINE INSURERS, Coast Guard officers and an evening of agony with a former friend. After running aground on a less shore, this skipper-person confessed that the boat he bought three weeks ago still was "missing" an anchor. So thump, thump, thump went the keel as each new wave floated his anchorless boat a yard or two closer to the rocks.

Charless F. Chapman's "Piloting, Seamanship and Small Boat Handling" is every Bay shilor's bible. Lectures Chapman: "The one right thing to do immediately after grounding is to take out an anchor and set it firmly." I remembered that line while trudging across the mud, through shoals of stinging jellyfish, to pass our towline to a powerboat. Nevermore.

Builders explain that local conditions and customers' preference dictate the auxiliary equipment installed or stowed aboard a sailboat. Indeed, there are dozens of different anchors -- Danforths, mushrooms, plows, etc. Each anchor's holding strength depends on the bottom, and each sailor has a favorite anchor, true, but builders' advertising evades the central question:

How can a boat, any boat, especially a 30-foot yacht, be sold "sail-away" (for $25,950 in 1978 dollars) with no anchor whatsoever? At issue is a real boat, not a figment, a popular "performance cruiser/club racer" built on the west coast of Florida, a yacht neigher worse nor better than competitors -- in short, a typical product.

What, then, does a purchaser get for $25,950 plus tax? He gets a seilboat, two sails, two batteries, four winches, a bow pulpit, one compass, one bilge pump, foam cushions, an alcohol stove and other "standard equipment." And standard it is, just as Ford might boast that seats and tires are standard with each car purchased.

"Optional accessories" may be ordered with the boat, and for safe operation, creature comfort and sailboat protection, these seem essential: A 150 percent genoa foresail ($718), a mainsail cover ($7.2), a grounded rigging system ( $250), double lifelines ( $130), one double berth ( $250), V-berth filler ( $60), a complete shower ( $750), masthead and spreader lights ( $130) and bottom paint ( $150).

But this is just the jumping-off point. Although the "sail-away" price has climbed from $25,950 to $28,460, the yacht remains at the builders until the buyer produces another $1,630 for "freight and commissioning" charges. Not always are such charges mentioned in the builder's brochure. In the case at hand, they are not. Subtotal: $30,090.

At this point, the buyer can sail away safely (after purchasing that anchor, the life preservers, mooring lines and a horn), but he still must steer clear of Maryland and Virginia water police. Bay cops not only will board an unregistered sailboat, they can fine its owner. Sail away safely, yes, but that yacht was advertised as a performance cruiser/club racer, and its purchaser, presumably, anticipates a weekend or a week afloat on the Chesapeake.

The next question is obvious. What does a skipper need to buy, and how much must he pay, to enjoy days followed by nights on the water? It seemed logical that the world's Largest charterer of bareboat (without a captain) sailboats, Caribbean Sailing Yachts, Inc., would have the answer. In its sales brochure, Caribbean Sailing Yachts lists "equipment common to all CSY boats," more than 50 items of equipment to increase the safety of customers, the lifespan of vessels and the comfort of charterers. They range from a dinghy with outboard power to sheets, blankets and pillows to a horseshoe life ring.

CSY's common-equipment list was taken to one of the largest ship's chandleries on the eastern seaboard, where a cooperative manager agreed to price the items stowed aboard CSY yachts. The manager was instructed not to use top-of-the-line prices or bargain-basement prices, but to shoot for the happy middle. Off went the manager with calculator and scratch paper.

.The total CSY inventory, he said, could be purchased retail for $6,755.22. In fairness to the builder, a few CSY accessories come with the 30-foot, performance cruiser/club racer, but very few. To get the vessel's "cruising price," therefore, $6,755.22 must be added to $30,090 -- the vessel's real "sail-away" price. Having invested $36,845.22, the owner now owns a fully found, fully equipped boat. Right? Wrong.

CSY's common equipment list has failed to please the ship chandlery, which points out that the world's largest yacht charterer skimps on foul-weather gear, basic electronics, "man-overboard" strobes, hand-held spotlights, an engine-parts kit and other seemingly sensible gear. So add another $1,546.78, briinging the boat's "all everything" price to $38,392.22.

Now the good ship "Drywell" chugs from the dealer's dock, bound on its shakedown cruise for Oxford, Tilghman, Tangier and Sharps Island. Its bow slices through the water, mermaids sun on its foredeck and the crew grins at their skipper. Too soon it's time to return home. At the Washington Sailboat Marina a 30-footer can be berthed for $522 a year, a bargain price for deepdraft sailors, but still $43.50 a month.

Now factor in insurance costs (about $300 a year for minimal coerage), annual hauling and maintenance costs (about $700 a year with bottom paint), breakage and replacement costs (about $200 a year). If these figures seem high, remember that in a chandlery, every can of varnish, every yard of line, every metallic gizmo, is double the price of its Sears & Roebuck counterpart. Chandlery salesmen mumble constantly about the corrosive effect of seawater and the ultra-violet rays in sunlight to push their products.

This is an attempt to portray, realistically, the cost of buying a 30-foot yacht, sailing it safely and comfortably and keeping it ship-shape and seaworthy. A builder's "sail-away" price is the first clue and little more. Yet few sailors are intimidated -- if boat sales, boat registrations, boat-show attenance and slip rentals are accurate indicators.

As a billionaire is supposed to have said: If you have to ask how much it costs, you probably can't afford it.

As columnist William F. Buckley actually said: "Owning a yacht is like standing under an ice-cold shower tearing up thousand-dollar bills."

No one, apparently, is listening.