Martha Spencer clings to the tall yellow leg of the oil rig, her speargun tucked close to her torso, the waves smashing violently against her.

The seas are rough today, a sunny and otherwise pleasant Friday in June. But a heavy breeze moving across the Gulf has brought choppy waters, with swells of up to 5 feet — far from ideal diving conditions.

With every passing wave, Spencer is pushed harder into the rig but manages to hold on, steadying her breath while clutching steel beams covered in barnacles and rust before she's ready to make her descent.

A couple of deep breaths and then she's gone — head first, the tips of her fins the last thing you see before she disappears into the dark indigo water. It feels like an eternity before she appears again, although in reality it's probably closer to 30 seconds or a minute.

When Spencer does resurface, she isn't alone: A 36-pound barracuda is tucked under her left arm, the tip of her speargun lodged in its body as she swims it back to the boat. Spencer struggles to hoist the fish on board before taking off her fins and pulling herself up onto the deck, where she can finally assess her prey.

She's caught a big one.

Spencer, 34, is part of a small but growing group of women who spearfish competitively in southeast Louisiana, considered by many to be one of the best places in the country for this high-adrenaline pastime.

The sport is popular all along the Gulf Coast, from Texas to Florida, but the oil rigs and pumping stations that pepper the Gulf of Mexico coastline near the mouth of the Mississippi River are considered prime hunting grounds for spearfishers looking for large prey.

Amberjack, grouper, cobia, red snapper, mangrove snapper and barracuda are ubiquitous in the waters here, with divers often spearing fish that rival themselves in size and weight.

The rigs are also among the most challenging places to dive: The inflow of sediment-laden water from the Mississippi River often creates a layer of murk near the surface that limits visibility and can extend down for 10 to 20 feet before opening up to reveal clear blue waters and thousands of fish.

Sharks are a common sight here, including the notoriously unpredictable bull shark species.

And the extreme depths — some of the rigs stand in up to 400 feet of water — can often be misleading and dangerous, especially if a fish ends up dragging a diver down well beyond the recreational dive limits or if they run out of air.

Likely because of this, the sport has garnered a reputation for being a high-risk, male-dominated and testosterone-fueled sport. Many who spearfish competitively join clubs, groups of divers that compete at annual rodeos and belong to the Louisiana Council of Underwater Dive Clubs, an umbrella organization that keeps score of the yearly records.

But until now, there were no clubs exclusively for women, and many of the clubs still prohibit female members.

Bristling at the discrimination, Spencer and her female peers decided recently to form the state's only all-female dive club, the Femme Fatales.

The club's members come from all walks of life. Some are graphic designers, like Skye Bailey Howard, or estheticians and business owners, like Abbie Woodward. Some work in the medical field, like Christy Perkins Stone, or as facility managers in the oil industry, like Cherie Hartley. Spencer, who lives in Madisonville, is a boat captain, deckhand and television host.

Summertime is peak diving season, and as the weekend approaches, the coolers are filled with ice and stacked with boat snacks and beer, the gear is assembled and packed, and come Friday afternoon, the women are on their way to the marinas of Golden Meadow, Port Fourchon and Grand Isle, among others.

It's not the first time Louisiana has had an all-female dive club. In the 1970s, a group of female divers — many of them wives or girlfriends of the all-male Hell Divers club — formed their own group called the Sirens. The club existed for some years, but most recall it slowly disbanding around the early '90s, and since then, outlets for women looking to competitively spearfish have been scarce.

Stone, a veteran spearfisher and diver, helped form the Femme Fatales club after growing frustrated with the lack of female participation in the sport. Stone and another longtime competitive diver, Woodward, had been talking about creating an all-female club for several years but didn't have enough members.

"I started seeing more free-diving women around the area and the girlfriends of some of the guys that were diving jumping in the water and trying it, but there wasn't any outlet for them to go and no clubs that they could get into," Stone said. "I think the more women find out about and know that other women are doing it, the more people will get interested."

Stone was first introduced to the sport in 2006 when she was in her mid-30s. She recalls her first trip out to the rigs as a nightmare: The weather was terrible, the boat broke down and several people got seasick.

"At (that) point I was like, 'I'm never doing this again,' " Stone said. "A year later, we went back, and it was a beautiful day and I shot my first fish. And ever since then, I've been hooked on it."

When Stone started diving competitively, the only other women she came across were Woodward and her mother, Claire.

The club's founders needed at least five members to join and have voting rights in the Louisiana Council of Underwater Dive Clubs, of which Woodward — a record-holding lifelong competitive diver — is the current president.

After months of phone calls and posting extensively on social media sites, they finally had enough women to form a club. The Femme Fatales now have seven members. By comparison, some of the longstanding all-male groups like the Hell Divers and Sea Tigers have anywhere from 30 to 45.

Competitive spearfishing is done either with scuba gear and air tanks or by free diving, also called skin diving. In the latter, divers essentially hover on the surface with little besides a mask, snorkel, fins and a speargun. When a diver sees a fish of interest below, they take a breath and dive, sometimes staying beneath the surface for several minutes while they shoot and then wrangle their catch back to the surface.

Divers who use air tanks can usually bring in a larger haul by pausing to hook each of the fish they shoot to a wire ring — called a stringer — attached to their hip. In most fishing tournaments and rodeos, free divers and tank divers compete in separate categories.

The sport is not for the faint of heart and it can be risky: With scuba diving, there is always the chance of lung over-expansion or decompression sickness, also called the bends, which occurs when a diver surfaces too quickly. Free divers risk what's called shallow-water blackout — when a diver loses consciousness from cerebral hypoxia, or holding their breath for too long.

Stone, who spearfishes with air tanks, says developing safe diving techniques ultimately can be the difference between life or death.

"In itself, without the sport of spearfishing, just as a diver there are dangers involved," Stone says. "But when you add to it big fish and cable that you can get wrapped up in, you can run out of air, you can hit your head on the rig . so you have to pay attention to everything."

Stone learned her lesson the hard way a few years back, after shooting a large amberjack in deep water. When her finger became entangled in the cable attached to the fish, she was dragged well beyond the recreational dive limit of 130 feet before finally managing to free herself and shooting to the surface. Miraculously, Stone survived and didn't get decompression sickness, something that is almost unheard of with that type of fast ascent.

"You learn from mistakes and you hope that you live through those mistakes but that it makes you better each time you do it," Stone said. "But it is a total adrenaline rush, whether you're male or female, and that's what keeps me going back for more."

At 48, Stone is petite but feisty, and frequently competes in the rodeos each club holds throughout the year. She recalls a Hell Divers member a few years back admonishing her about setting her hopes too high.

"He said to me, 'Little girl, you will never shoot in the land of 50-pound amberjack,' " Stone said.

At the annual Hell Divers rodeo this June, Stone took home a first-place win after catching an 84.5-pound amberjack, the largest fish caught during the competition by a man or a woman.

Stone approached the same Hell Divers member and asked him if he recalled what he said to her all those years ago.

"I told him, 'I guess you're going to have to eat your words now, right?' "