THE SETTING: MARINE-RESERVE islands off Mexico’s Pacific coast. “A friend will drop me half a mile offshore in an area where poachers are known to be, as the sun’s going down,” says Scott Cassell.
“I’ll swim in using a LAR-5, which is a combat dive rebreather worn on the chest, and my head, shoulders and back covered in a ghillie suit (camouflage gear), carrying a whole bunch of kit.
“Using night-vision on my camera, I’ll film underneath the poachers’ boats in the harbour what they’ve been killing, then I’ll bring the camera up so I can get their matricular number, as evidence.
“Doing a dive like this right under their noses is how I got a boat-hook in the chest a couple of years ago. They will try to kill you if they see you, and I still have a nasty scar. All the gloves are off with these guys.
“When I’m done filming, I’ll leave the harbour and find an area in the rocks where I can hang out till it’s completely dark. I’ll crawl out, take off my wet kit, open up my dry-bags and put on my camouflage outfits. With my cameras, which include GoPros, I’ll do a sniper crawl until I’m almost in their camp.
“I’ll stay there motionless as a bush for up to two days. Very little water, just enough so I don’t die, and no food, because the last thing I need is to have to use the rest-room!
“I’ll film them constantly day and night. I’m collecting what they say and do, because that’s evidence.
“I’m pointing out their faces, the GPS position, date and time, and the action, which is usually killing and cleaning animals. I’m getting real intelligence, just like I’m doing a recon mission in the military.
“On the second day, after they’ve gone to bed, I’ll crawl my tired, sorry body out of there. As soon as I’m over the hill I can stand up and walk over to where I’ve buried my dive gear and I’ll reverse – put all my dry stuff in the bags, put on my dive-kit and try to stay warm until a particular time.”

AT THIS POINT SCOTT CASSELL deftly inserts a plug for his sponsor Luminox, but it’s entirely in context.
“The Luminox dive watch is essential to this type of operation,” he says. “It’s very durable, and without using lights the little dials will stay illuminated for about 20 years. The last thing you want is to have to put on a light to make them glow, because the bad guys can see it, and that’s when you can take a bullet.
“That’s why it’s used in special operations all the time. It has no battery, either – good for the environment.”
A tough timepiece comes in useful. “Apart from the boat-hook, I’ve been run over by a boat, stabbed in the back, had a guy try to crush my head with a rock and had to fight my way out of it.
“You also fall over on rocks running in the dark. I’m amazed that the crystal isn’t even scratched!”
Cassell’s buddy will be a mile offshore at a pre-agreed GPS co-ordinate and time. “I swim out on a compass course. After about 1500 kicks I’ll pop up and be almost impossible to see from shore. Then I’ll backswim to the intersect point and stay there ’til I see his panga coming.
“We don’t have lights on the boat because the drugs cartels don’t use lights. If you use lights, you’re not drugs cartel. I would rather have the drugs cartels not mess with me than the police, because both of them will kill me, but the drugs cartels will be a lot meaner about it.
“If the military come up, we’ve got permits, and hopefully they don’t open fire on you first. The drugs cartels will just come by with AK47s, sink your boat and kill everybody aboard.
“I’ve done dozens of these missions and they’re always scary, not least under water. You’re 20ft deep on a compass course and never know what’s going to swim by. I’ve seen some pretty big animals and had no idea what they were!
“I’ve had a bioluminescent tube pass by that’s as big as a marlin or a whale.
If it’s a dolphin you hear it clicking, but when some silent behemoth goes by you think, oh crap, what was that
“There’s a very large population of great whites in the Sea of Cortez, too – they go there to give birth. This was discovered ‘officially’ last year, but I’ve known about it for 10 years.
“I’d like to do this sort of work full-time. I hate a bully. Three years of my life were spent in combat in the US Forces and I’ve seen bad people do bad things. But I would give my life to save a single shark – that’s how much I love these animals.”

I HAPPEN TO BE READING a Jack Reacher novel on the train on my way to meet Scott Cassell. If you haven’t read any of Lee Child’s thrillers, it’s all-American murder and mayhem revolving around an ex-military crime-fighter, and very hard to put down. Recommended for any dive-trip.
In the hotel, drinking the first of a chain of coffees in the best-lit corner of a lounge, I find a slightly smaller version of Reacher.
Just minutes into what will be a two-hour conversation, I am as absorbed in the quietly spoken Californian’s extraordinary, and often violent, world as I had earlier been in that of the fictional tough guy.
Cassell is in London representing Luminox, and to discuss with the BBC a possible upcoming underwater series.
His CV is somewhat overwhelming. With his father working for the US space programme, his childhood was spent constantly moving home and state.
He started diving at 12 and in 1977, inspired by Jacques Cousteau, blagged his way into becoming a commercial diver – the USA’s youngest underwater welder. He was 15.
He became an aquanaut, too, using an underlake habitat built by his boss, and recalls watching metre-long catfish eating chicken bait through the window.
That fondly remembered summer set his trajectory: “All through my military and my civilian career I’ve found my way to the ocean,“ he says.
Diving-related qualifications range from open water to commercial diving instructor, and mixed-gas rebreather diver to cave-diver, while long service in both the US Army and Navy brought with it multiple roles.
He was one of only 10 advanced diving medical technician instructors in the States, and a Navy diving and diving medical supervisor. He reckons to have spent 13,000 hours under water.
A merchant-marine captain and qualified submersible pilot, he was also a hyperbaric medical technician instructor at the College Of Oceaneering.
Crucially, he was a counter-terrorism combat dive and sniper instructor for Special Operations personnel, a path he pursued as an independent contractor after leaving the military.
I’ve met hardcore conservationists before, but never one like Cassell. Eleven Mexican poachers are serving long jail terms as a result of the sort of “mission” described above, and 14 more currently face sentences of eight to 10 years.
“In America there are too few park rangers, and you can slaughter 25 dolphins in a Californian marine reserve and all you’ll get is a ticket,” he says.
“Mexico is at war with the drug cartels, so its resources are stretched very thin and a lot of animals go unprotected, but its law will still prosecute poachers, and they go to prison for a long time.
“So Mexicans are far better at loving their environment than Americans are. I’m trying to rub America’s nose in that, because it should be ashamed of itself!”
He turned to poacher-hunting after a counter-terrorism operation in Iraq ended his combat career. “I was stabbed twice, once in the body armour and the second time in my spine, which paralysed the top of my left leg.
“Before I could turn round my buddy blew the man’s head off, so I didn’t get the satisfaction of killing him myself.”
Later, on a diving expedition in Mexico’s Sea of Cortez, he located a population of the almost extinct giant white seabass, only to find that these “totuaba”, along with dolphins, turtles and sea-lions, were being targeted illegally by fishermen.
When his subsequent surveillance operations started getting them arrested, the culprits would refer to their usually invisible tormentor as the Sea Wolf, and he changed the company name to Sea Wolves Unlimited.

I MENTION A LETTER PUBLISHED in DIVER in April concerning the rumoured plight of bull sharks off Cancun, thinking it might interest this lone wolf, even though he usually operates on Mexico’s west coast.
“It’s true, I saw it myself just a couple of months ago,” says Cassell. “We were there talking to Dive Balam, the people who dive with the big bull sharks in Playa del Carmen.
“Marcos Mier started the programme, and I won’t say that he’s tamed them, but he’s conditioned them to be around people in a non-aggressive state.”
Twelve to 20 sharks will show up almost on cue, attracted by the boat sounds, and be hand-fed. “You don’t want to push bull sharks, but these are calm animals.”
So would the Sea Wolf intervene in Cancun “I have, and I will again. There is a particular fisherman there who loves to kill bull sharks, and if he can’t sell them he throws them in the dumpster and Facebooks it. He’s proud of it.
“He laughs at everybody who dives with sharks; he laughs at me – he’s taunting me to go out there and get him. What he doesn’t realise is that I will.
“Fishermen who kill a bull shark are thieves – they’re stealing an income potential from their society and the community for their own selfish gain. They should be outlawed and treated as criminals.
“I show audiences pictures of Mier playing with bull sharks and of me playing with great whites and tiger sharks – my babies. These animals are not only misunderstood but a draw for people to see.”
Cassell reckons certain fishermen aim to kill as many sharks as they can there before an inevitable ban is imposed.
“Protection of these sharks needs to come this year, so if you love sharks, go there now and support them,” he says. “The Yucatan is on the edge of making it or completely losing it.
“People get paid to go out and fish, but try to get paid for protecting fish – we’re way outgunned. When I get the opportunity I jump on it, but I usually have to pay for it from my own pocket.”
Next year Cassell takes his two-man K250 submersible Great White to Cancun to dive with the bull sharks and to seek out invasive lionfish in deep water, collecting them using a suction pump. “Among other things we want to train bull sharks to eat lionfish!” he says.
Any other activities are likely to be rather more undercover.

GREAT WHITE ONCE BELONGED to a doctor who hoped to locate cash on a drug-runners’ aircraft the FBI had forced into the sea. He failed, and left the sub rusting in his garden for 25 years.
Cassell bought it for $10,000, and reckons it has cost about $75,000 of his and backers’ money to make it operational, though contracting out the work would have cost 10 times as much.
“Now it’s one of the safest subs I’ve ever seen,” he says.
He started his non-profit-making Undersea Voyager Project (UVP) nine years ago. Funded by donations – including profits from Luminox’s Scott Cassell UVP watch – Great White has done 1000 dives to as deep as 160m for up to 10 hours at a time.
The UVP programme is aimed at teenage scuba-divers, including those with disabilities. “I teach them about the sub and let them do dry dives and dive around it in the shallows.
“We then take four to 16 kids on each of our expeditions. They undergo intensive training before being allowed to pilot it at shallower depths.
“Four times a year, they have to give talks to other kids about what it’s like to be an undersea explorer, and how mankind’s presence under water is very important. It’s not just about sending down ROVs – if people don’t take the risks of exploring, we’re not really inspiring anyone to enter that field.
“Great White is extraordinarily inexpensive to operate and we can take it almost anywhere. Last year we did more than 300 dives for less than $30,000.”
This year he’ll ship the sub to Tioman in the Philippines to survey reef sharks, and in August takes it hunting for six-gilled sharks at Catalina Island.
Then it’s back to Lake Tahoe, where in 2009 the team found a sunken forest of 3500-year-old trees. He hopes to prove that they got there through a landslide.
Cassell also pilots a bigger tourist and research submersible called Seamobile: “That’s a Hummer – our sub is more like an old Willys Jeep, designed to be beat to hell.” And he is building an underwater floating habitat called Pelagic Voyager, built from discarded steel, and powered by wind and sun, that will take two people for up to 10 days.
Income from Cassell’s TV work supplements donations for all his unpaid underwater activities. He has been making underwater films for 15 years, including a Last Chance to See with Stephen Fry for the BBC in 2009, but mainly big squid and shark specials for the US adventure channels.
Through these he is associated with those huge Pacific battering rams known as Humboldt squid, and was the first person to film giant squid in the wild.
However, when History Channel licensed the result to the US Monster Quest show and the voiceover almost doubled the already impressive 54ft stretched length of the animal, he was not happy.
It wasn’t his only run-in with Monster Quest, either. “I was looking for great white sharks in the northern Sea of Cortez, but when the programme aired they said I was looking for megalodon.
“What They’ve been extinct for 65 million years-plus, and I was looking for a real creature! And we found one.
“I immediately jumped in the water, and the cameraman jumped with me. Then he realised it was a great white, and got out right away. He left me there to die, so we never got any extra footage of great whites. We’d made a very valuable find but it never made it into the show. That’s why I’m here to talk to the BBC!“

TWO YEARS AGO, CASSELL recorded an unratified world record for longest distance travelled by a diver – 52 miles in a 9.5 hour non-stop saturation dive, using a tow-glider of his design.
And last year he planned to cover the 30 miles from Catalina to San Pedro Harbour on a continuous scuba dive while surveying for the blue sharks that are fast disappearing from California’s kelp forests – “it’s tragic, because it’s such a beautiful shark”.
A near-fatal equipment failure forced him to abandon any idea of a record and surface. “The team responsible for part of my life-support was, let’s say, not up to snuff. I almost died when I inhaled water into my right lung. I recovered it under water, but realised I’d need a medical assessment.
“When I surfaced, the dive medic realised I was in pretty bad shape. I lost consciousness but I recovered enough to get back in the water within half an hour, and completed the remaining five hours. It was hard, but I don’t give up.” Not a single blue shark was seen.
Cassell’s partner Kerry chips in: “You were out of it but the medic gave you some glucose and within a few minutes you were sitting up and telling a story, and we said: Scott’s back online!
“But we were shocked when you got back into that water.”

WHEN I ASK IF THE COUPLE DIVE TOGETHER, it turns out that just three months earlier a terrifying entry-level experience had almost ended Kerry’s life.
She had opted to learn to dive in the usual way, with a Californian dive-school. “I was doing a mask clearance and got some water in my regulator, which was making me uncomfortable, so I ditched it and went for my secondary.
“The instructor pushed my hand away and tried to make me put my primary back. I tried to go to the surface and he pulled me back down and hit me in the face with the regulator by accident.
“I inhaled water in both lungs but the instructor didn’t realise. He stayed kneeling on the seabed, holding onto me.”
Fortunately, Cassell had been observing the class from a distance. “I’ve been diving for 35 years, and it was the worst thing I’d ever seen,“ he says.
“This guy pushed me away twice, the first time under water. I gave him five seconds to solve the problem and I never should have done that, because that’s what caused Kerry to go into a coma.
“Then I pushed him out of the way, grabbed her and took her up. He surfaced and pushed me away again.”
That instructor couldn’t have picked a worse fight. “The very first sound I heard from Kerry was gurgling through a lot of inhaled water, and the only time I’d heard that before was when a friend got shot in the chest in Iraq and his lung was full of blood. I had to save him too.
“So I was thinking no, not my girl!
He tells Kerry to calm down. I waited two seconds, ripped his mask off and pounded the s*** out of him, just to get him to release her.
“I could have gone a lot further and I’m kinda proud that I didn’t, because it felt so good to hit him.“
Cassell towed Kerry 300m to shore and “started screaming for someone to call 911. She was on life-support for two days, and they sucked enough water out of her lungs to kill two people.
“The woman I love almost died right in front of me.”
“Other than in the submersible with Scott, it’s hard for me to imagine going back in the water,” says Kerry quietly.

CASSELL’S STORIES ARE OFTEN GRIM, but he laughs a lot too. I wonder how he squeezes in all his activities.
“I have a lot of free time because I don’t need much sleep,” he says. “I’ve seen a lot of bad things in my life, and when I sleep they come to haunt me.” He’s awake about 19 hours a day.
“I’m just a regular guy,” he insists.
“I use Special Ops techniques, but you don’t have to be a Green Beret or Ranger or a Navy Seal to do this kind of thing, you just have to have the heart.
“Everyone individually can do something to save the oceans and make a difference, and that’s the message I want to convey.”