For some guys, a Harley Davidson would do it. For others it takes a Fender Strat. Me? I entered a Big Game Fishing tournament in Tobago.

Yep, turning 40 is a weird experience for a guy. It’s not enough that we have to watch all our bits drooping and find ourselves shouting at the TV, we’ve got to ward off middle-age by doing something so out of character that it makes all sane people tut-tut with amazement. Up until that fateful fortieth year, I’d never caught the Big One - a billfish. But I’d dreamt of it, and that was the driving force. I had tried a couple of blue-water trips whilst on holidays in various exotic places, but it’s not the same - to catch a specific species needs focus. And the impending birthday provided just the focus I needed.

Interestingly, marlin fishing has only really opened up as a viable mass-market sport in the last couple of decades. It was only in 1903 that the first ever billfish, a striped marlin, was caught on rod and line and a mere decade or so before that, the first tuna were caught on rod and line. Tackle and techniques are still being developed specifically to deal with these tough opponents properly and we still know very little about their distribution, lifestyle, breeding and feeding patterns. Similarly, the growth of affordable and accessible long-haul flights mean that anglers from the colder climes, like Scotland, can now actually get to where the fish are.

Everyone is still learning how it all works as they go along and I like that about it. It feels like you are getting in at roughly the same level as everyone else and pioneering with the best of them. There are some real experts of course, people like Peter Goadby and Peter Wright, but even they admit to learning something new each and every season. There are no hard and fast rules to this sport. Not yet at any rate and I have watched the crews in Mexico only recently "learn" how to use circle hooks and bridled baits - things that were being used almost ten years ago elsewhere.

Of course, you catch a whole lot more than marlin when fishing for marlin. To be honest, you hardly catch any marlin at all when fishing for marlin, but that, in a strange way, is the point of it all. A bit like salmon fishing writ large, but with a few alternative species thrown in to save the day. Some fisheries count marlin strikes as well as fish hooked and caught in order to beef up the numbers (and therefore talk up the game) using a strange etiquette like “angler “A” went 4 for 2 on the blues”, which means that four blue marlin were raised and struck by angler “A” but only two were actually caught.

Thankfully there are loads of other exciting blue water game fish to keep you occupied whilst waiting for a marlin strike: wahoo (named after the Hawaiian Island of Oahu, not the sound you make when you hook one), dolphin (also called dorado, mahi-mahi or felusi depending on where in the world you are fishing), kingfish (king mackerel), and, inevitably, tuna in a variety of flavours. The latter are great to catch, but are bruising, determined fighters. There used to be a bluefin tuna fishery of some note off Scarborough in England when the herring were plentiful back in the 1930’s, and I believe that bonitos and bluefins are now showing up off the west coast of Ireland. Tuna can tolerate temperate waters more than other blue water game species because they have a special blood vessel arrangement in their muscles which warms up their blood, making them less dependent on their environment for their body temperature and therefore their energy levels. They are, to some degree, warm-blooded fish.

But for me, there is only one real blue water quarry - marlin. Well, let’s extend that to “billfish” as there are several species to choose from. There are spearfish (3 species) but they are rare and are usually an accidental catch, apart from in Hawaii where there is a regular spearfish run; and then there are sailfish, which are a great target species in their own right. Swordfish also fall into the billfish category, but I have yet to connect with one. Then there are the marlins proper: Black marlin, Striped marlin, White marlin (and some people sub-divide this again into white and hatchet marlin) and Blue marlin.

Blue marlin are huge fish, growing up to 2000lb in weight (although the rod-caught world record fish is a few hundred pounds short of that) and they have massive reserves of strength and power. They are, quite simply, the perfect pelagic (open ocean) predators. Unlike most other predatory fishes, they don’t have teeth. Instead, they have a long, hard, rough bill on their nose for stunning their prey before they swallow it, and their jaws and mouth area are as rough as sandpaper. They have that very specific scythe shaped tail which, straight from the design board of Mother Nature, is the fastest aqua-dynamic shape possible, driving them at phenomenal speeds through the water. No other fish can catch them. Their eyes are the largest in the animal kingdom relative to their brain and head size, and are specifically adapted for detecting and focusing on prey in the brightly lit top layer of the ocean whilst they power along in their high-speed life. They are, quite simply, unique: at the top of their tree and at the pinnacle of their evolution.

To catch them, you mostly pull up to 8 lures, or baits, in a pattern or “spread” for hours and hours across the ocean, although the most productive fisheries, in my experience, use live and dead baits. Local knowledge will set you near the baitfish that they feed on, or watching birds following or diving on the water can give a marlin away. But it’s mostly pulling lures or baits behind purpose built sport-fishing boats along undersea drop-offs or reefs, with a good skipper at the right time, in the right place and at the right speed that yields a result.

In 1998, just before my 40th birthday, I chartered a boat for a week in Gran Canaria and I almost realised my ambition. For about a minute I was connected to what was later estimated at about 700 lbs of very angry fish.

But, the fates conspired against me. The owner was Dutch and drunk for most of the time. The skipper of the boat was Spanish (but sober) and had never fished before. And the big blue was smarter than all of us. It took the smallest lure on the only rig with a reel that didn’t have enough line on the spool to hold it. When it struck, it was a scene as farcical as any in a Fawlty Towers episode; the owner yelling in Dutch, the skipper panicking in Spanish and me bewildered in Scottish. We tried to get the other six lines in. Pandemonium. They got me into the fighting chair and strapped the rod onto me. I could see smoke pouring from the reel as the line disappeared into the distance. More pandemonium in Dutch and Spanish as they realised the reel was running out of line… and then they backed the boat up over the rest of the lines fouling the propeller in the process. After taking around 500 mtrs of line in one unstoppable run, the fish won its freedom and celebrated in the distance with an imperious tail-walk… but I’m getting ahead of myself and giving some of the game away.

But think of that power - 500mtrs in about a minute or two dragging the equivalent of 130lbs (the maximum drag on the reel which we had to go to in our attempt to stop the fish and which resulted in the leader breaking). Awesome.

Of course, many of you reading this would have some sympathy with that fish and I have to confess that I was certainly glad that it lived to hunt another day.

When you see something so huge, so powerful, so beautifully vibrant and vital in its blue, green and gold aggression, it breaks your heart to see its carcass hanging, dull and grey, on the dockside scales with a grinning moron standing beside it. Well, I’m being a bit harsh here; not everyone who kills a billfish is a grinning moron - it’s fishing and it’s a blood sport. Sometimes, despite everything, the fish die or are killed. Besides, in many fisheries, even yet, all fish are killed as food or bycatch for the crews. In waters like Mauritius, catch-and-release hasn’t quite caught on yet and those waters are also wide open to long-line commercial fishing boats which are hoovering up just about everything, including most of the marlin. No angler truly knows what happens to his or her fish when they release it, but most would want to release it into an environment where it has a chance of survival - not into one where it could easily be scooped up in the next trawl.

You can catch marlin in almost all tropical waters but you have to watch the seasons as they vary from location to location. Marlin are highly migratory so you need to stick to the game fisherman’s maxim of go to the right place, go at the right time and do the right thing. Close to the UK, there is a reasonable fishery in Gran Canaria (although I failed to find any reasonable boats and crews but I’m sure they are around), and for a few years at least, there was an international star attraction in Madeira where you could catch a “grander” (a 1000lb fish) but in recent years it has fallen away, probably due to shifting migration patterns of the right kind of prey species.

A grander is really big stuff and it takes stamina to fight something that size. Try walking into the nearest field and wrestling a cow to the ground…get the drift? If you are lucky enough to get a big fish, you can be fighting her (all the big fish are females and all the more reason to release them in my view) for up to 5 hours and maybe more. Because of that, I usually put in a couple of months of fitness training prior to any trip and I do lots of running, rowing, upper arm, lower back, abdominals, triceps and wrist exercises to get up to scratch. It’s bloody boring to be honest but I keep imagining The Big One leaping out the water before me and it keeps me motivated. Just.

If you want to give it a go, there a couple of things you should bear in mind. First, it is not a cheap sport. A good boat and crew will cost anything from $350 to $1200, and possibly even more, per day depending on where you fish. Also, if you live far away from the destination, it is really difficult to tell if you are getting the right kind of boat and crew for that money. Caveat emptor.

Going at the right time can be tricky too. When I went to Tobago, I picked tournament time because I reasoned that no-one would hold a tournament when there were no fish. I learned later, though, that 1998 was the best year for marlin catches that they had ever had.

The next thing you need to bear in mind is the conditions that you are likely to face. The sun will fry you so you need to take plenty of high factor sun cream and wear t-shirts. You also should wear a hat, but that’s not as important as sunglasses. You absolutely should not go out on the water without a high-quality pair of shades. I did it and I succeeded in burning my retinas. It happened in Mauritius and I had gone out there with those driving glasses that you can buy - the ones that make everything brighter. Well, of course, they were useless on the water and caused my eyes even more discomfort. So I took them off and, well, what can I say? I got sunburn on the backs of my eyes. It hurt like hell and when I returned home I could hardly see for a day or so with streaming eyes and all such. Very worrying. So now, I have the best pair of polarised glasses that money can buy. You only have one pair of eyes after all.

Back on the boat, the crew, if they are good, will be courteous but busy most of the time so help them out by staying out of their way and not asking dumb questions at peak times of stress like when you get a strike. If you’re interested in what is going on, watch and then ask them to explain when things quiet down. Do exactly what the skipper tells you and talk with him before you start fishing to make sure that he knows you need help and that you need to understand exactly what he wants you to do when you get a strike or a hook-up.

This can be a dangerous business. If you’re using heavy line test of 130lb or more, it’s not impossible for the angler to get pulled overboard in the event of a reel jam or a tangle. Think about it: I weigh around 182 lbs (on a good day) so a sudden jar or jam on the line from a rapidly accelerating big fish could easily launch me out of the chair. The rod and reel combined weigh quite a bit too, and since they will be harnessed to me…well, I don’t like to think about how fast I would sink if I went into the water.

You are, sometimes, secured with a safety line (although to be honest the crew usually think more about the rods and reels and secure them with a safety line, leaving you to fend for yourself) but this is not always a great idea either. When the fish get boatside, they are often “green” and are therefore very lively. They can, and do, jump into the boat from time to time. I don’t think that I’d like to be secured to the chair if that happened.

Also, if you have a big fish on and you get a sudden line break, it’s not unheard of for the rod to come whipping back up and smack you in the face. Broken noses can, and do, occur. I myself had a near miss in this way once and your chances increase if you are holding the rod with your left hand whilst using heavy gear. The best way to fish with heavy gear is to have your left hand on the reel cover to guide the line and act as a stopper on the rod in the event of a break. You need to learn to take all the strain on the harness and resist the temptation to lift the fish with your left arm. This takes some getting used to, but it’s better than a night spent in a casualty unit. Especially a developing nation’s casualty unit.

Success can take a lot of sea-time - the casual one-day-fishing-while-I’m-on-holiday angler will be very lucky indeed to catch a marlin, but it does happen of course. If you are fishing in a group, it lessens the chance of your rod being the one to hook the fish, but it alleviates the potential boredom of long hours trolling with foreign crews and limited conversation. Each to their own.

Of course I wouldn’t recommend this at all if you get sea-sick or are spooked by the ocean. Trolling at around 7 knots on seas of up to 9ft, anything as far as 20 miles from land is not everyone’s idea of an idyllic day on the water and when the wind gets up and the sea spray dries like sharp sand on your skin it is not at all comfortable. There is also the possibility of an accident at sea; once when trolling off Gran Canaria we ran down a large swell and narrowly missed, of all things, an 8ft long chest freezer bobbing just under the surface. If we had hit it, it would have made a sizeable hole and with the state of the rest of the gear on that boat… well I don’t want to contemplate what the safety equipment would have been like. I can swim, but not 5 miles in heavy seas.

You’ll also need to stay in fishing friendly accommodation and have meals, etc. planned to suit your hours, as well as taxis or whatever to get you to and from the boat dock, often at ungodly hours of the day. The logistics are not for the faint-hearted in some places, but there are plenty of custom packages which are arranged specifically to suit anglers. The Americans have this down pat and I would recommend that first-timers booked through a well-known US outfit like South Fishing Inc who specialise in South America.

But no matter how much preparation you make, nothing, repeat nothing, truly prepares you for what happens when you fight your first fish. The tension and drama work against you all the time, tiring and exhausting you faster than you can exhaust the fish. The crew will be shouting at you to keep up the pressure on the fish and wind the reel whilst your arm is dropping off.

Years ago, it was all macho stuff where the angler would simply be left to fight the fish from a near dead boat. It made for brutal, bruising battles and both the angler and the fish were in pretty bad shape by the end.

Nowadays though, largely pioneered by American and Australian skippers, the trend is towards backing down or chasing the fish. There is a lot of sense, as well as humanity, in this. If you get the fish to the boat quickly it will still be green; that is it will still be vibrantly coloured and healthy. Fish that are totally beaten turn a drab bronze colour and if they are released it is more likely that they will die or fall prey to sharks. So if you are interested in releasing live, healthy fish, you need to get them to the boat fast and that means the boat is as big a part of the fight as you are. Even fish of 1000lbs and more can be beaten in as little as 15 – 20 minutes with a pro-crew and a motivation to save her life (not that I have personal experience of this – but I read the comics and dream…).  Mind you, it doesn’t always work like that and fights of 4 and 5 hours are not uncommon. There was even a record battle of 26 hours with, unbelievably, the marlin getting off at the leader come the end. I wouldn’t have liked to feel what that angler felt after that length of time. Especially losing the fish at the boat. Ouch.

Finally, if you do want to do it, make it soon. The stocks of all pelagic billfish are collapsing and are now only around 15% of what they were in the 1960’s. White marlin are, at the time of writing, on the verge of being declared an endangered species in US waters despite a spirited, and perfectly correct, campaign against the proposed legislation by the sport fishing community.

Sport anglers are not blameless in the overall decline, but nowadays the vast percentage of sport caught billfish are tagged and released. By the year 2000, an impressive total of 22,176 blue marlin had been tagged and released by members of The Billfish Foundation in a global tagging program, and of the total 31 marlin caught in the Tobagan tournament I fished in, 29 were tagged and released.

The commercial long-line and drift fisheries for tuna and swordfish do the real damage. These death machines set miles of monofilament netting or drag up to 52000 hooks spaced 40 inches apart. Each boat takes 42000lb of “product” daily from the oceans. Amongst this “product” are marlin, sailfish, spearfish, shark, dolphins and even small whales. The grotesque name for this is “bycatch” and in most countries it can’t be landed and is simply dumped over the side. Dead. An international disgrace.

Commercial fishermen have to make a living too, especially in poorer countries, but this is an unpublicised and unseen crime against the world community, on a larger scale than rainforest destruction. Something to think about when you buy your next swordfish steak or open your next can of tuna. The fishery scientists reckon that 88% of swordfish brought to the table have never spawned. And, believe me, there is no such “product” as dolphin friendly tuna.

If you are lucky enough to catch a billfish, be smart. Tag and brag.