Strolling about the docks, you can join the tourists gazing at slip upon slip of long, sleek yachts, the starched white bows gleaming in the sun, waves licking at the curvaceous underbellies as gently as a puppy dog's tongue. Now comes the captain - he strides on deck , kindling awe and fancy. Where did he sail from? Where is he going? what could be more romantic than life on a yacht?

Life on your yacht.For these captains are chauffeurs, albeit of the Rolls Royces of the sea - and the roles they are frequently called upon to play are not always easy for proud, self-reliant salts.

They must be both priest and doctor, ditch-digger and diplomat, plumber and nursemaid. They tend another man's children, pulling erstwhile schoolmates along on skis behind the runabout. They keep scuba tanks filled, cajole icemakers into cranking cubes properly for gin and tonics, chill the champagne and elicit speedy service from harbormasters in foreign ports by offering trinkets, made-in-U.S.A.

For the skippers of th rich, yachting is hardly as carefree as it seems.

They may lose the helm at any moment to corporate takeovers and divorce. Nasty property settlements can hit the boss where it hurts; alas, the yacht is usually the first to go. There are long, seasonal stretches away from family, though separation anxiety usually gives way to a stronger urge - the itinerant life at sea.

It is a calling of sorts, 24 hours a day, 365 days a year. And, though there are stretches of peace in between, the captains to waterborne gentry must be ready to sail when the boss is.

Most important, they keep the boss off the rocks, maintaining a fierce vigilance over the ship's whimsical innards - lest the desalinization gear break down and require loud throat clearing and polite supplication for the boss' wife to, pleasr, forgo the bubble bath for the engines' sake.

Discretion is their watchword; resumes are only as strong as the last command. The salary is usually in the $15,000-$30,000 a year range (depending on ship siza and the skipper's reputation), an adequate recompense, perhaps, if one considers the benefits - room and board, maybe a company health plan, a ration of independence, plenty of salt air and, above all, an unobstructed ocean view.

It is the life they hace chosen, and most would have it no other way. "If a man was paid to run a yacht by the hour, he'd be as rich as the boss," says one veteran skipper. "You do it because you love the life, not the money."

"I don't want to dig ditches and it's better than working in a meat packing plant!"

Meet Big Loy Tantalo, skipper of the Reetz, a 60-foot, $125,000 Pacemaker cruiser owned by a New Jersey meatpacker. Tantalo is a heavyweight presence with a foghorn laugh, a lusty appetite and a salty tongue. Which, of course, is understandable and perfectly okay in a chief bosun's mate, retired, which is what he is.

Chief bosuns reign over the Navy's deckhands - the gang of unheralded, highly mortal men who specialize in work so dirty (scrubing, painting, greasing anchor chain, etc.) even magic cleansers can't keep them clean. On dry land, they lend to vent their lot through fun-loving, barroom recreation. But Neptune is said to be understanding, reserving them a special place beside his watery throne. On dry land, chiefs like Tantalo keep watch over the flock.

So, the other day, it was not unusual to find Big Lou, 56, engaged in a colorful lie-swaping contest with good old boys at the dockmaster's shack in Annapolis. He was trying to pass off a school of fish stories that would make Larry Flynt blush, cackling over an allegedly eventful trip (wine, women, song, etc.) up the inland waterway from Boca Ratona, Fla., where the Reetz spends the winter.

Suddenly, it was time to cast off. Bud White, the Reetz's owner, had arrived.

"Gotta go," said Lou, who has known typoons and waters smoothas silk. He has been married and divorved; two daughters married sailors.

After the Navy, he fretted as a dockmaster in Myrtle Beach, S.C. "I still has salt water in my ears." Then one day he was pumping gas into the yachts of "all these guy who called themselves 'Captain,' and I said to myself, 'Lou, if they can be captains, so can you.'

"It's been a good life . . .not like the nine-to-fivers'. We're different . . . We ever get cut, we bleed saltwater, not blood."

The arrangement has been equally pleasing to owners like White, whose pasty complexion testifies to long hours making deals behind a desk. He is a typical commander-in-chief. Most are businessmen who use their boats to escape boardroom pressures. Others find the sea works another kind of magic on prospective clients, looling signatures - pronto - onto the sotted line.

"You can talk business on a boat better than in a restaurant and you don't have to wear a tie," says White. "You get your points across, uninterrupted. A boat is a great place to make a deal."

On the high seas, it pays to be prepared. Ruthless drug smugglers are said to be on the lookout for cheap transport. Unarmed pleasure craft are easy prey, and you cannot sit around with the skippers for five minutes without hearing tales of shadowy threats.

A hijacked yacht is found floundering, abandoned at sea, the captain and passengers mysteriously vanished, the sickly sweet smell of fresh-cut marijuana lingering in the hold. Another boat, reported missing for a time, is found in pieces, apparently dynamited after off-loading high-priced Columbian from a "mother ship."

A soft-spoken stranger in denim, fold and turqoise dangling about the neck, appears dockside with a briefcase. It is stuffed with hundred dollar bills. A cruiser is bought on the spot - for cash - and later scuttled.Feverish tales of drugs and money and violence.

No wonder men lik J.D. Munn, 60, skipper of the 90-foot J-Mar, comt to suspect every dockside stranger in search of work, and reach for a fun whenever a curious boat hovers too close. Munn keeps a high-powered rifle, a shotgun and a flare pistol aboard the $2 million yacht he skippers for New york art dealer Lawrence Fleishman, who doesn't like guns.

"But we need them for our protection," says Munn, who armed himself last winter when a scruffy ship with no flag approached the J-Mar off the coast of Nicaragua. "If they'd come any closer, I'd have let them knoe they wouldn't board me . . . You shoot a flare pistol into a boat, it makes a hell of fire." He grins.

Life is winding down aboard the J-Mat. Capt. Munn, an articulate, leather-faced man who tracked German subs up and down the East Coast for the nCoast Guard in World War II, has just sailed into Annapolis from West Palm Beach, Fla., the J-Mar's winter home. The owner is expected to arrive any day with family for a summer cruise up the coast to Maine and Nova Scotia. J-Mar's two crew members are preparing for leave.

The first mate is off to visit family; the J-Mar's very own Waldorf-Astoria-trained French chef aims to ferret out other amusment.

"A girl in every port," grins Robes Harris, 28, a New Jersey cosmopolitan who has garnished his Christian name (Robert), cultivated a rakish red beard and softened a tres American accent with a whiff of gay Paree. "It's just like they say. You meet a lot of chicks in this job. And at a certain time of year, they're all saying, "Hey, Robes should be getting here any day,"

Capt. Munn's wife and two grown children live in Palm Beach. He usually stays aboard in port, retiring to quarters to write letters and read adventure novels. Underway on the maritime dreamboat, painted pin-stripe, there is no rest for the crew.

The sophiscated electronics gear alone is enough to make the late Werner Von Braun drool. To find his way, all Capt. Munn has to do is punch a few buttons and the computerized, satellite navigation system whines nd whimpers and tells him precisely where he is. There is a back-up system for every back-up system.

The custom yacht was molded from the bottom up by Stephens Marine of Stockton, Calif. The owner conferred almost daily on the design with naval architect Jack Hargraves. The J-Mar lacks no amenity.

A spiral staircase from thebridge glides gracefully into three luxurious staterooms. Bathrooms are bigger than the Holiday Inn's. The master bedroom has a queen-size bed, walk-in oak closet and a color TV (one of three aboard). Nor does the boss ever have to leave his quarters to know where he's going - a fancy bank of navigation instruments stares from a desk.

The J-Mar can cross any ocean on one tank of gas. Never mind if she veers out of television range and fuzzes up "Saturday Night at the Movies." All the folks have to do is plug a video-casette film into the Betamax.

Should guests find themselves topside and turvy, they need only amble past the glassed-in living room and dining room to the wet bar - which stands ready to settle that queasy feeling. Coke, root beer, Tab and soda water spurt from the tap at 42 degree. Hungry? Call Rober.

And, lest boredom intrude, there are toys. Deep sea fishing gear, diving duds, three underwater scooters, two runabouts, one Hobie Cat and several decks of cards. An air compressor aft will fill scuba tanks in a snap. Munn earns $24,000 a year keeping it all together.

Livelihood as a yacht captain is a far cry from his dream in the 1930s, when Munn aimed to hook a reputation as a crackerjack sport fisherman. He set about chasing marlin to Bimini, where he saw Ernest Hemingway flatten a native in a fistfight. "The guy challenged him and Hemingway knocked him cold as a cumber - one punch - and just walked away, never said a word."

In 1947, he squirred a 17-year-old Elizabeth Taylor deep-sea fishing. "She was a little bit spoiled, but who that famous isn't?" He helped a teenage Freddie Woolworth, of the five-and-dime family, land his first tarpon.

It's all in a scrapbool. Financially, Munn just couldn't stay afloat; he gave up the dream.

The son of a freight schooner operator who ran mail along Florida's west coast, Munn always wanted to put to sea, and over the years has tried to avoid turning into a "white collar skipper." Which means he gets dirty. The J-Mar's engine room is so clean, add butter, and you wouldn't mind frying an egg in the oil pan.

The ship costs $200,000 a year to run, but Munn figures he saves the boss money by doubling as engineer. "We try to watch the dollars. Mr. Fleischman has to work hard to keep up the boat and pay our salaries."

Skippers do not view their yachts as extravagance. Says Munn, "I'd do the same thing if I could afford it."