There's a black-and-yellow sign on the door of Tom Angel's office at the Santa Fe Diving Co. that says succinctly: "Caution. If you think OSHA is a small town in Wisconsin - you're in trouble.

The same sign can be found on the doors and desks of the people who run a dozen commercial diving firms like Santa Fe, whose shops and offices are 60 miles south of New Orleans on the way to the oil rigs and pipelines in the Gulf of Mexico.

The signs are at Sub Sea International in downtown New Orleans and at Taylor Diving & Salvage across the Mississippi River in suburban Belle Chasse. They're 400 miles west at Ocean Systems in Houston and 600 miles east at Long Diving in Jacksonville.

"We keep these signs around to remind us that OSHA says we have to guarantee a safe workplace," said Angel, who manages 70 divers doing repair and construction work on the floor of the Gulf of Mexico. "Now our workplace is the bottom of the sea and I ask you how in the hell you can guarantee safety on the bottom of the sea."

OSHA, of course, is not a small town in Wisconsin but the Occupational Safety and Health Administration, a branch of the Labor Department created by Congress to watch-dog safety in American industry. Only six years old, OSHA now has 2,500 people on its payroll. More than half carry the title 'Inspector' to their jobs, which is to enforce safety at 5 million workplaces employing 65 million Americans.

OSHA and the country's commercial diving contractors are locking horns over safety standards for divers.

OSHA thinks commercial diving can be made safer through regulation. The divers believe diving is inherently dangerous, that you can't make it any safer than they've made it and that attempts to regulate it can only ruin it.

There's no question diving is risky. Divers say abour half have lost fingers through careless handling of knives or the strong nylon ropes they use underwater. Many divers are hard of hearing. That's because of eardrum damage caused by constant pressure changes divers undergo moving up and down in their workplace.

But divers say the undersea is not as hazardous as the public thinks it is. No commercial diver has ever been killed by a shark, for instance. Barracudas are considered more dangerous, but only because they're more curious than sharks. They're also easier to scare away.

The major marine life danger to divers is the grouper, the huge and clumsy bottom dweller whose lack of teeth and wisdom make it take in everything along the sea floor for food. One divers was sucked in from the bottom of the Gulf of Mexico last summer until he was in the grouper's mouth up to his chest.

"He hit him on the nose, he pulled on his line and his topside tender pulled on his line," recalls Taylor Diving's James Eberle, who would not identify the other diver. "The grouper finally spit the diver out and let me tell you it was a couple of days before that diver went back to sea."

OSHA has tried for almost two years now to set safety standards for the diving industry, which has never been regulated. So far, the fight has not gone OSHA's way.

Most recently, OSHA lost a federal court test over the emergency diving safety standard it set, one that diving contractors say is not needed and is too expensive. According to the Council on Wage and Price Stability, the emergency standard could cost the diving industry from $33 million to $100 million a year. The latter figure is more than the industriy grosses annually.

The wage and price council's $33 million number is its estimate of what it would cost the diving industry to prevent two diver deaths a year, or about $16 million a life. In the most recent study on the subject, the Coast Guard suggested the value of a human life be set at $370,000 for the purpose of setting standards.

The divers' battle began two summers ago when the United Brotherhood of Carpenters and Joiners petitioned OSHA to set the emergency standard because safety conditions in the Gulf of Mexico - where 90 per cent of the commercial deepsea diving is done - had become "abominable."

It should be pointed out that the carpenters: Washington office is next door to the new Labor Department building, where OSHA is housed. It should also be pointed out that the gulf has largely been closed to the carpenter union, which represents many inland water divers because of its 50-year connection with the pile drivers and bridge builders.

Out of the more than 20 contractors diving in the guld, the carpenters have won the right through elections to represent two. Ocean Systems in Houston and the J. Ray McDermott diving Division near New Orleans. Neither firm has signed a contract with the union, which claims it represents as many as 700 divers in the guld. The contractors say there aren't 700 divers in the United States, muxh less in the gulf of Mexico.

If the carpenters say they've got 700 gulf divers in their union that means they've got 700 guys with union cards that say they're divers," said Santa Fe Diving's Tom Angel.

The number of commercial divers is important to the issue of whether the industry should be regulated. The carpetners say there are 2,300 commericial divers in the United States, a statistic OSHA is using. The diving contractors say there are no more than 600 commercial divers, working, in the United States, meaning the industry is too small to regulate.

The contractors claim the carpenters and OSHA have counted divers they employ in the North Sea and the Persian Gulf.

OSHA counted divers listed in many cities Yellow Pages, the contractors also say. "The've got at least 400 divers in their tally who dive on weekends and in their spare time for nickels and dimes," Angel said.

Central to the issue of diver regulation is safety, which is in hotter dispute than the divers'numbers.

OSHA took statistics from the carpenters union that said there were more than 20 deaths and 60 serious injuries among divers in the Gulf of Mexico in the last seven years. The contractors challenge those numbers, saying the carpenters tallied diver accidents the way Chicago's aldermen used to count votes.

Angel said he saw the name of a diver working for him listed three times on the accident sheet, each time with his name misspelled. Taylor Diving's president, Ken Wallace, said the carpenters listed the death of a diver who still works for Taylor. The carpenters deny they juggled names.

OSHA is also using underwater accident figures compiled by the University of Rhode Island's John McAniff, who has studied diving hazards with a grant from the National Oceanic and Atmospheric Administration. McAniff found 41 underwater deaths in the last seven years, including six offshore - five in the Gulf of Mexico and one in the Santa Barbara Channel. Most of the rest, he said, came in rivers and habors, where salvage makes up most of the diving and risks run higher because of the busy waters.

Commercial diving contractors dispute 16 deaths on the list, saying divers for treasure, abalone, seaweed and black coral are not commercial divers and shouldn't be counted.

Taylor Diving has lost five divers in 20 years, one struck in the head by a tree being carried down the Mississippi River and anothe sucked into a pump on a dredging job.

A third was caught by a wire that cut off his air supply; he panicked tore his helmet off and drowned trying to reach the surface.

The most recent fatality in the gulf involved a diver being brought up slowly in a diving bell to avoid decompression effects. Exhausted, he asked if he could turn off the diving bell light so he could sleep. He was told not to extinquish the light, so he put his shirt over the light to dim it. The shirt caught fire, which raced through the pressurized bell and burned up all the oxygen in seconds. The diver died from seared lungs.

Divers in the gulf are well compensated for taking risks, which might explain why they're hesitant to be unionized or regulated. They are paid by the foot in the depths they dive. Taylor employed 17 divers last year who made more than $60,000, five who made over $70,000, six who topped 80,000, and three more than $90,000 Taylor's top diver last year made $96,000 for about nine months's work.

The first between OSHA and the diving contractors will intensity in the next few weeks. Hearings are to be held this week by the House Select Committee on the Outer Continental Shelf to decide whether to give OSHA jurisdiction with the Coast Guard over offshore diving. At the same time, OSHA and the Coast Guard have been told to write in the next 30 days the first legal safety standard governing commercial diving.

If the new standard is anything like the emergency standard OSHA came up wiht nine months ago, it, too, could wind up in court.

OSHA did not help its case the way it wrote the emergency standard. It wanted divers autopsied at death so doctors could study the effects of diving on their bones. It wanted a paramedic diver standing topside in a suit to help a diver in trouble. It wanted backup radios to communicate with divers in the water and backup instruments to monitor every step the diver took along the ocean bottom.