They were also easy to find. We just needed to spot the diving birds, who were feeding on the smaller fish that had been brought to the surface by the school of tuna. But tuna also spook easily and, as quickly as we got alongside them, they would dart off hundreds of metres.
The birds followed. We followed. We fished. We didn't catch anything.
"You can get 20 tuna in an hour sometimes chasing birds," Justin says. "Or nothing. It's the story of my life."
Justin was an Aussie who had come to the Yasawa Islands to fix a friend's boat and never left.
He now fixes or maintains anything that has a motor at the Mantaray Island Resort and also runs fishing charters on the side. I noticed his boat was called Rogue. It seemed appropriate.
Leo and I weren't the only ones along for the Great Tuna Chase. Meuni, a giant of a man who grew up in a nearby village and who had no need for ocean charts after his grandfather taught him where every reef was in surrounding waters, was driving the Rogue.
There was also a Bollywood actress from Mumbai on board to add a bit of glamour. She had come to Fiji to escape the glare in India - apparently "everyone" knew who she was. I didn't know who she was.
She had never been fishing before but was hooked, just like the first fish she reeled in. Unfortunately it was a scad mackerel, a smallish cousin of the tuna, but a fish nonetheless.
Leo hooked a tuna at one stage which must have been about as big as him and weighed even more but it escaped. Everything and everyone seems to want to escape when it comes to Fiji.
The school of tuna darted off again. The birds followed. We followed. It was as close as we got to catching a tuna but, far from being dispirited, it was some of the most exciting fishing I have experienced.
There were thousands of them all feeding frenetically, it's just that none of them were in the mood to feed us.
Fiji's waters are alive. The previous day I had been diving among a cacophony of colour as the likes of parrotfish, trumpetfish, eels, turtles, flatfish and stripy fish swam among the coral reefs and underwater gardens. It was breath-taking, and peaceful, and the gentle currents made it an easy dive.
Tavinico Point, just off the coast of the Yasawa Islands, is a world-renowned dive site.
On the other side of the island, manta rays come to feed on plankton and krill between May and October.
Snorkellers can easily swim with these magnificent creatures that can grow to 7m wide and live until 70. They cruise up and down the channels with their mouths wide open and flap their massive wings, looking like some prehistoric creature from The Flintstones.
They all have names. One with a white shape on its back that looked like a love heart was called Cupid and another with a growth that looked like a middle finger being raised was Big Bird. All had scratches or marks where they had been attacked by sharks. I soon found out what that was like.
As we finished our fishing trip by cruising up and down a small reef close to the shoreline, Leo reeled in a queenfish.
I then hooked a giant trevally. It was a good-sized fish and was putting up a good fight. There was a good reason for that. Suddenly a grey reef shark took an enormous bite out of the trevally. The line went slack. I reeled in what remained of the hapless fish and found only its head, marvelling at the precision of the shark which was able to leave behind what it probably considered the equivalent of brussels sprouts on its plate.
I had to chuckle. If it wasn't Leo's board shorts, sharks in the water were also scaring the fish.
Checklist
GETTING THERE
Fiji Airways flies from Auckland to Nadi with return Economy Class fares starting from $380. fijiairways.co.nz
ONLINE
fiji.travel mantarayisland.co
