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Spearfishing yellowfin tuna

yellow150The yellowfin tuna is one of the most formidable species to target. They are extremely fast, strong beyond belief, and wary of divers.

A 60 pound yellowfin is easily capable of drowning a diver, should he or she become caught in the floatline.

When to hunt for yellowfin tuna:

All year round… somewhere!

Where to hunt for yellowfin tuna:

Atlantic and Pacific oceans in warm water. Top spots include South Africa, Ascension Island and Guadeloupe.

Behaviour and hunting:

YFT inhabit clear warm water and are constantly on the move. They will be attracted to concentrations of baitfish and will often be seen breaching and smashing small fish amidst circling and diving seabirds. The fish are so fast that you usually have just one chance- and thats if you are lucky.

To hunt YFT please contact us by email as we will be able to discuss your specific requirements.

As a rule of thumb, you will need a 140-160cm railgun with double 16mm rubbers, a 30m RA floatline connected to a 2m Bungee, then an 11l Hard Float, then a 3m bungee connected to a 35l float. Shooting line should be dyneema or 400lb mono. Reels should NOT be used for this fish (its run will completely overwhelm a gun or belt reel).

There are two broad approaches:


Ideal for smaller and medium tuna. Deploy the boat with a drogue sea anchor and prepare for a long drift in water deeper than 75m. Alternatively you could tie up to a deepwater moring, but the former method covers much more ground. Beforehand you should catch about 100lbs weight of jacks or other fish and tie these at intervals to a stern line.

The divers should position facing downstream and take it in turns to chum the tied fish, cutting them into little cubes which will drift down current. All manner of fish are attracted and you may see wahoo, dorado, amberjacks, sailfish and tuna coming to investigate. Unfortunately tuna will come in at attack speed and their erratic movements will often evade a rain of long range spears from the frustrated divers above! Efforts to dive on the fish often result in the fish retreating to 30m+ and eating the chum out of range. One approach is to wait for the speeding fish to pass, then dive to the chum level and assume a mid water agachon in the hope that they will return to the chum and bypass you to get the food. This approach does yield results.

The obvious downside is that you may attract something that might eat you, necessitating a rapid exit! In August 2011 Tony and Titus were using this exact method and were horrified to raise not a tuna but an 18 foot tiger shark!


Looking at the ratio of tuna caught by the team in ASI, about 80% are freeswimming. 100% of the yellowfin over 100lbs were caught freeswimming. This means no chumming, and opportunistically encountering yellowfins in the open ocean.

Hence, for Ascension at least, the team increasingly favour freeswimming pursuit. This involves the divers swimming along the edge of a deep dropoff or other likely spot, hoping to spot a big tuna in the good vis and make an approach. The approach is described in full detail in the dive report below.

Dive Report:

The armour plated head of a huge tuna landed by Titus in January 2011. This natural protection will deflect anything but the most powerful speargun with a tri cut tip. Spears often bounce off the armoured heads so we advise you use Rob Allen spears with tri cut tips.

“On one particular day we headed out to a spot we call ‘fishtank’ on account of the calm, clear water and abundant life. A photographer’s dream, and where we take most of the underwater shots of captured game. Cam, Rory and Penny had newly arrived and stayed in the shallows getting used to the kit and looking for jacks and taking pictures. Penny found a blue spotted flounder she wanted to photo and called Rory to look at it – he promptly shot it LOL.

Tony was used to the spot having landed a couple of fantastic 30lb atlantic jacks a day before and we paired up and headed straight for the bluewater at the edge of the island. I found the dropoff and we swam parallel, Tony slightly inshore. Well used to the conditions I spotted a 200lb plus YFT (you can tell the size from the length of the scythes) swimming in the opposite direction, but on a parallel course about 30m away right on the surface. I’ve had good success with my technique for freeswimming YFT so immediately went to full speed, abandoned my flasher and aimed for a point about 5m ahead of the fish’s path. I rapidly closed distance, never swimming directly at the fish. Slightly concerned the YFT turned in the water, so it was facing directly away, range 20m. I increased speed and pursued it directly, waiting to do a blindside move. As predicted, the YFT wanted to see what I was now doing, and I saw it start to turn to its right. Immediately I turned left into its blindspot, anticipating the fish making a quick turn to the left now. As the huge tuna started to swing left, I was already swimming hard to the right. By now range was about 16m.

The tuna resumed its original course, with a slight leftwards arc to try and get a view of me. Aiming still 5m ahead of it and going flat out, it looked like an intercept would be possible. I closed to 10m, the fish getting bigger and bigger in view, but instinctively knew I was not in range. This is when fate intervened and another 200lb+ YFT joined from the left, heading the opposite way to my fish. This second fish was bigger, but I had burned up too much energy on the approach to change target.

My fish hesitated (all the time I’m coming in flat out!) and broadsided at about 8m range. I made a shallow intercept dive to 3m, now swimming directly at the fish’s flank, it was slowing down to turn and follow the other tuna. IN RANGE- I lined up on the centre of the fish and pulled the trigger. Nothing happened. The safety had got knocked on the boat it seems. Cursing, I took my eyes off the tuna, freed the catch and looked back, expecting it to be out of range. However it had turned in front of me and was now at 5-6m range. close enough. The 160 carbon was fitted with double 16mm rubbers and 7.5mm shaft for maximum range and impact. I carefully steadied my aim and fired. I didn’t even have time to see if I had hit it before the gun was pulled from my grasp and the line was running fast. I hitched a ride on the float and a protracted battle ensued, diving from an anchored boat, I was well out of my comfort zone and the big fish was hell bent on dragging me out to sea. To make matters worse, a 10 foot Galapagos shark turned up and started circling me. At this point I was still supported by Tony, and made the decision to send him back to alert the rest of the team and come get me with the boat.

Somewhat reluctantly Tony handed over his 140 railgun and made the swim back.

After about an hour of solid exertion, the boat showed up to rescue me and I cant express how glad I was to see it. By then the fish was dead and I was pulling him up. The expectant shark was thwarted.

A fantastic fish and a memorable battle!”


10/10 Eat as sashimi, or seared on the BBQ as rare steaks!

Weapon of choice:

With no doubt the gun for this fish is: Rob Allen Carbon Railgun, 160cm with double 16mm rubbers and 7.5mm spear

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