Taking the Plunge : The Delta, a Jules Verne-style sub-for-hire, plumbs ocean depths doing scientific tasks and searching for sunken treasure from its base at Ventura Harbor.

An on-board crane gently lifts the little yellow submarine off the mother ship and plops it into Ventura Harbor. Climbing down to the sub, a burly silver-haired man squeezes into the conning tower, closes the hatch and circumnavigates the harbor.

Tourists on the docks stop to gawk at the strange metal craft, no bigger than a compact car. Somebody asks, “Can you rent one of those?”

The answer is yes. But your harbor cruise will cost $3,500 a day, with another $3,000 for the mother ship, plus expenses.

The sub-for-hire is the pocket-size Delta, which, despite its Disneyesque appearance, is a serious research vessel. Certified to dive to 1,200 feet, it is used primarily for scientific endeavors--mapping underwater earthquake faults, tracking crab populations. But the two-man sub is also rented for more exotic missions, such as searching for sunken Spanish galleons or exploring fabled wrecks such as the Lusitania and the Edmund Fitzgerald.

“I talk to guys every year wanting us to find Amelia Earhart,” says Rich Slater, the man inside the sub.

Slater, a 57-old marine geologist, is not looking for the missing aviator in Ventura Harbor. He is taking the Delta on a short test run before its midnight departure aboard the mother ship Cavalier, a 110-foot utility vessel leased from Buccaneer Marine Ltd. of Ventura. Slater’s company, Delta Oceanographics of Oxnard, has been contracted by the Scripps Institution of Oceanography to find lost current-reading instruments in the Santa Barbara Channel.

“There ain’t a lot of work out there” for subs, says Slater’s partner, Doug Privitt, a taciturn, self-taught sub-builder. “But there’s enough to keep us busy.”

The Delta is one of only a handful of private research subs in use today and probably the most active, Slater says. Stubby, ungainly but remarkably safe, the Delta has logged 85 dive-days and 318 dives this year and close to 3,500 dives in 12 years.

The 15 1/2-foot, 5,000-pound steel cylinder looks like the brainchild of Jules Verne’s Capt. Nemo in “20,000 Leagues Under the Sea” but was actually designed and built by the 63-year-old Privitt. It has 19 bug-eyed ports and several protuberances, including mechanical and hydraulic arms. Eight 12-volt batteries power the screw, producing a cruising speed of only 1 1/2 knots, a slow walk.

British sports cars are roomier than the Delta. Instruments such as sonar, a computerized navigation system, gyroscope and Fathometer line the sub’s interior. The pilot sits on a bench amidships, his head poking up into the conning (observation) tower. Wedged in, the passenger has to curl up in the padded nose section.

When the hatch is sealed shut and the Delta drops into the black ocean on a quarter-mile descent, the pilot and passenger look through 1 1/2-inch-thick Plexiglas, their field of vision illuminated for 20 or 30 feet by two side-mounted lights. The pilot controls his depth by either filling storage compartments with water or using compressed air to empty them. Regardless of the depth, the pressure inside the Delta remains at one atmosphere, the same as on land.

“The sub’s a simple design,” Slater says. “Everything’s mechanical.”

THE TREASURE SEEKERS

Slater figures that 95% of Delta’s work is scientific--it does a lot of diving for the National Oceanographic and Atmospheric Administration--and the rest of its time is devoted to “the wild-goose people.” It seems everybody with a treasure map and a snorkel knows Delta’s Oxnard phone number. Slater and Privitt are continually approached by speculators who want them to lower their rates in exchange for a percentage of the alleged booty. Occasionally, they agree.

“Gold always sounds good to us,” Slater says.

But they haven’t got rich. Once, they were lured to Florida by a treasure hunter’s secret map, but “all we found were a lot of fish holes,” Privitt says sardonically.

A year ago, the Delta went looking for the Brother Jonathan, a paddle-wheel steamer that sank in 1865 off the Northern California coast, supposedly with $2 million in gold and $250,000 in U.S. Army payroll on board. With Chris Ijames and Slater’s son Dave taking turns piloting the Delta, and Privitt along as observer, they found the wreck “not where it was supposed to be,” Privitt says. “Everybody else had looked in the wrong place.”

Is there treasure aboard? Nobody knows, says Slater, because the state is holding up exploration of the wreck pending a court battle over salvage rights.

Slater has been tempted to go after the San Jose, “the richest Spanish galleon of all time,” he says. The ship rests somewhere at the bottom of the sea near Cartagena, Colombia. But treasure hunters are deterred by the Colombian government, which would insist on keeping the San Jose’s contents and putting them in a museum, Slater says.

“Some people approached us about sneaking into Colombia,” Tackett says. “No way we’re going down there illegally.”

Slater says they could pull it off. Privitt gasps. “No way I wanna spend time in a Colombian prison.”

The Delta’s crew faces hazards and potential disaster on every mission, but the sub has never had an accident. “I don’t have any worries about the integrity of the sub,” says Ijames, a 35-year-old Santa Barbara resident who regularly pilots the Delta. “It’s a real workhorse--you can even bang around rocks. My only worry is getting tangled.”

In the summer of 1993, Ijames got tangled. The Delta was diving off the Irish coast, doing work for marine biologist Robert Ballard who was filming a National Geographic TV special about the Lusitania, the British luxury liner that was sunk by a German U-boat in 1915.

On the Delta’s second dive of the day, an old line snagged the sub’s tail at 300 feet. But Ijames didn’t panic. Privitt had designed a safety feature for this very predicament. Ijames simply unscrewed the tail from inside the sub and the tail dropped off, freeing the sub, which bobbed to the surface. About an hour later, the crew guided the Delta--now fitted with a backup tail--to the wreck and retrieved the missing piece.

If the Delta becomes disabled, a 180-pound lead weight can be jettisoned, allowing the vessel to rise to the surface. If some alien force drags the Delta down, it is capable of withstanding pressure at 1,800 feet.

Leaks do occur. “Minor leaks once a while,” Privitt says. “No big deal. I just hitch up my drawers.”

Enough oxygen is on board to keep the crew alive for 72 hours and give rescue workers the necessary time to reach the sub, Slater says. But despite precautions and safety measures, tragedy can strike without warning. In 1970, he and Privitt were each piloting a Nekton sub, a forerunner of the Delta, on an assignment to recover a racing boat off Catalina. After the boat was hauled up to a surface ship, it broke loose, plummeted at an angle and collided with the submerged Nekton.

“There was a one-in-a-million chance of it hitting us,” Slater says.

The collision cracked a port by Slater’s head, and the glass imploded. It gouged the right side of his face and a rush of water flooded the sub, which plunged to the bottom, 225 feet below the surface. Dazed, Slater was able to open the hatch. He and his crewman scrambled out.

“All I could think was, ‘I’ve got four kids--I have to get back to the surface,’ ” Slater said.

The crewman didn’t make it, but Slater, an experienced diver, ascended for 2 1/2 or 3 minutes before reaching daylight, he estimates. He was found floating face down, unconscious and not breathing. He was treated at a Catalina hospital.

Slater, whose face still bears the scars of the accident, is listed in the Guinness Book of World Records under the category “Underwater Escape . . . the greatest depth of an actual escape without any equipment has been from 225 feet by (Slater) from the rammed submarine Nekton Beta off Catalina Island, Sept. 28, 1970.”

Slater believes he also has the unofficial world record for making 2,500 dives in submersibles. “Except for the guy running the Disneyland (sub ride), nobody has ever made that many,” Slater says.

Slater and Privitt first met in 1969. Privitt was designing and building Nekton subs for General Oceanographics in Newport Beach when Slater came aboard as chief scientist and sub pilot. Slater, an affable fifth-generation Californian who grew up in Santa Paula, has a Ph.D. in marine geology from the University of Sydney. The grizzled Privitt has built a dozen subs despite a formal education that doesn’t go beyond junior college.

Raised on a farm in rural Missouri, Privitt grew up without electricity and built toy graders to amuse himself. A mechanical wizard who pilots planes and has competed in motocross, he got involved with minisubs in the early ‘50s when he moved to Southern California. He “met a guy with a sub in his garage,” he said. “I had always thought about making one.” Privitt’s first sub was launched in 1959.

Privitt, who is married and has three grown children, has made more than 800 dives in his subs, but his main role takes place on land, “fixing things and keeping everything going.” Working in his computerized machine shop in Torrance, Privitt overhauls the Delta once a year. He is currently “doing some thinking” about building a new sub, possibly from titanium, which would extend the sub’s range to 3,000 feet.

THE BODY IN THE LAKE

In the mid-’80s, he and Slater formed Delta. It was a risky venture: Both had either worked for or owned similar enterprises that had failed, including General Oceanographics. But Slater had spent a lot of time all over the world and “knew there was a need” for a research sub.

Delta received national publicity last summer while navigating near the wreck of the Edmund Fitzgerald, the iron-ore ship made famous in a 1976 song by Gordon Lightfoot. Filming a TV documentary, Delta’s crew descended into Lake Superior to try to determine why the 729-foot vessel sank during a 1975 storm, with all 29 on board perishing. While the dive yielded no definitive answers, the Delta did find a body, which had been preserved under 525 feet of icy water.

“We were kind of lost in sediment and were trying to get our bearings when my passenger looked out and saw (the body) right next to us,” Ijames says. “It was like looking at a mummy.”

Ijames also was the pilot on the search for the missing Scripps current-reading instruments last month. He and Paul Harvey, a development engineer at Scripps’ Center for Coastal Studies, looked for the devices for three days, combing the ocean floor off San Miguel Island. They found only one of three lost instruments, but Harvey calls the search a success. “We got much more back than the cost of the mission,” he says.

Now that their assignment with Scripps is finished, Slater is working on Delta’s 1995 schedule, which may include a trip to the Galapagos Islands in the spring. Also in the works is a hush-hush project for a foreign government to find and recover a military jet that crashed in the Pacific.

Missing from the ’95 schedule are rides around Ventura Harbor.

“Back in the late ‘60s and early ‘70s we’d take people on rides all the time,” Slater says. “It’s fun, and I’d love to do it now, but then we’d be like a ferry boat and need different registration from the Coast Guard. Because of that and liability, we just don’t do it.”

A harbor cruise wouldn’t be that much fun anyway.

“It’s too murky to see anything,” Slater says.