It could be the antics of bubble-blowing divers, but it seems it is only misfit loner dolphins and the odd pod which get as big a kick out of divers as we do from them. John Bantin, with help from John Liddiard and Ralf Åström, sets out to nail the questions surrounding diver-dolphin encounters.
You have to stimulate a spotted dolphin - just get them wake-surfing, jump in the water and don't stop moving, says John Liddiard
A clear blue sky over a slightly choppy, tropical sea; islands dotted with palm trees on the horizon; a boat driving in large circles at high speed. We weren't lost and we weren't searching for a wreck. It was all part of a strategy to swim with spotted dolphins on the Bimini Banks in the Bahamas. A day before, I had joined the live-aboard Sea Fever in Miami. Originally built to ferry crews to oil rigs in the Gulf of Mexico, the 35m aluminium dive boat made short work of the crossing from Miami to the Bahamas. A couple of warm-up dives and a night tied up at Bimini, and we were up for an early start. looking for dolphins. Having found some, the trick was to get them in a playful mood. They liked to ride the wake of a boat, but would give up if we took them too far from where they wanted to be. With the boat describing large circles, the dolphins could join and leave the boat-chasing and wake-surfing game whenever they wanted, without straying too far from their friends and relatives. Clutching cameras and videos, and with fins, masks and snorkels in place, we lined up on the swim platform. It was impossible to see what was going on, but the message came down from the bridge to be ready. The note of the engines changed as the captain put them in neutral. The boat was still drifting forwards when the dive master shouted: 'Go go go!' and we launched ourselves into the sea like well-trained paratroopers. A mass of bubbles, a quick camera-check, and I just had time to look through the viewfinder before the first dolphin came zooming past. With a quick barrel roll he dipped beneath me and banked to circle the group. I managed to shoot a few frames, probably of a bit of tail and my own fins, because everything was happening so fast I took a deep breath and dived for the white sand 10m below. Above me, other divers were swimming with a purpose; they obviously had a dolphin in sight. One dived below them, rolling and turning from side to side, swimming a high-speed slalom between their feet. Curiosity aroused, he was heading straight for me, but there was never any question of a collision. He was constantly in motion, teasing me to try to turn as fast as he could. My lungs bursting, I swam hard towards fresh air, twisting all the time to keep the dolphin in view. Below, one of the other divers was swimming to the seabed. I watched from the surface as a group of dolphins converged, then spiralled around him. They hit the seabed in a bomb-burst manoeuvre, like the Red Arrows, spinning out in all directions before turning back to spiral around the now-ascending diver. A few more passes left the divers widely dispersed. I looked up to see the skipper signalling for us to regroup. A tight knot of divers formed while Sea Fever headed off in another series of big circles, gathering dolphins for some more wake-surfing. The boat turned in close and glided past, its engines cut. A massive wake bobbed us up and down, then the dolphins were back and the diver-teasing continued. After 20 minutes the dolphins had finished, and so was my film. We climbed back aboard to rest and reload. Similar in shape to bottlenose dolphins, these creatures are born a uniform slate-grey colour, acquiring spots slowly as they age and acquiring the full suite of mottling only on reaching maturity. They use their sonar to detect flatfish and other animals hiding in the sand, then a quick snuffle and dinner is easily caught. Large communities of spotted dolphins live on the Grand Banks and Bimini Banks. These dolphins and other cetaceans don't like divers' bubbles, which is why we had to leave our aqualungs on the boat and snorkel. Like many intelligent mammals, they are not interested in anything static, but want to play, hence the strategy of getting them interested in surfing the boat's wake. A similar approach was needed in the water. The dolphins ignored divers who just floated and watched, but immediately joined anyone diving to the seabed or turning somersaults. The boat cruised gently forward, while on the flying bridge above us the captain looked out for more dolphins. Once spotted, Sea Fever accelerated and began to circle until they were surfing the wake again, but this time I was not so lucky. Once in the water I got only a glimpse before the dolphins were gone. We waited for 10 minutes but to no avail. Perhaps we were impatient and jumped in before the dolphins were hooked on the surfing game. Back on board, we cruised the banks looking for more dolphins. It took a while before we found them, but once located they were soon enticed into playing behind the boat. Now more cautious, we accepted a long wait on the swim platform while allowing our friends to become well and truly hooked on the game. The delay was worthwhile, because third time was definitely lucky. Half a dozen dolphins, including a mother and calf, decided to join the fun and spent several minutes formation-flying round us, as we repeatedly dived and somersaulted to entertain them. Breaking formation and swooping in from the side, a dolphin made a tight S-turn and came to a momentary halt, looking directly into my lens. If dolphins could wink, I am sure there would have been a mischievous flip of the right eyelid.