It was a curious spectacle. Off the shore of one of the Kona coast’s largest hotels, several boats had gathered in the night. One by one, they turned on large floodlights, illuminating the inky blackness with their glows.
A gigantic mouth suddenly looms out of the darkness, all-encompassing wings flapping as a manta ray swoops down upon you
Divers plunged in, followed by flotillas of snorkelers dangling off lighted rafts. We stood on the shore and watched them, jostling figures in the lapping waves. For a while, nothing happened.
Then, through one of the lighted patches, I could see a large shape momentarily illuminated, then another. The shapes we were watching were manta rays, and excited snorts and submerged exclamations drifted up from the snorkelers as the mantas swooped below them.
It was a pretty unique opportunity to see these animals from the shore, but definitely not enough for me – I intended to see these ocean giants up close and personal for myself.
So it was a few days later that I found myself powering along in a dive boat with six other intrepid souls, heading for a different manta ray site just off Hawaii’s Kona International Airport.
The sea was calm, and we were ushered along by occasional pods of bottlenose and spinner dolphins, along with the last of the winter’s humpback whales.
Big Island is famous for its manta ray dives, and justly so as there can be few places in the world where you can be almost guaranteed to see them. For a wildlife experience, seeing mantas is pretty awe-inspiring – the ‘wing span’ of the oceanic mantas can reach an incredible seven metres and they weigh as much as 2,400 kg. That’s a lot of ray.
Essentially consisting of a gigantic mouth with languidly flapping wing-like fins, these enormous animals’ diet consists entirely of microscopic plankton – tiny drifting organisms that include the larvae of fish, crabs, sea urchins and eels, tiny krill and plants. These are vacuumed up in unfathomable quantities as the mantas swoop and glide about in the open water.
Our boat powered to a stop and we were finally at our destination – Garden Eel Cove, home to the mantas along with, as the name suggested, a large number of garden eels.
We suited up, had our briefing, and dropped over the side of the boat. With a gurgling woosh I deflated my buoyancy control device and slipped beneath the waves, dropping 10 metres to the sea floor.
We made our way along the edge of the reef and descended still further, eventually coming to a sandy area that stretched off into the deepening gloom. There before us were the infamous garden eels – hundreds of them poking their serpentine heads out of the sand, swiveling around to watch our approach.
As we got closer they disappeared back into their holes, like watching some sort of inverted Mexican Wave, and soon they were all gone.
I glanced back as we continued the dive to see their little heads cautiously reappearing, all but muttering to themselves in annoyance.
Back on the dive boat we realised that our previously quiet cove had become the nexus for every dive boat on the Kona Coast. Small dive boats, luxury dive boats, catamarans and skiffs all sat at anchor, with divers and snorkelers milling about in the twilight.
After warming up and changing tanks, we watched the sun set and darkness fall, the blues of the sea deepening into a more formidable black. Then, it was time for the main event.
Diving at night is quite a different experience from diving during the day. Your world is centered on the sweep of your torch, with blackness pressing in around you. It’s hard to get a handle on how far down you really are, and easy to lose your dive buddies.
Couple this with 50 plus divers descending into darkness, many of them novices, lights waving about frantically as people tried to get their buoyancy corrected. This was made even more chaotic by a heavy ocean swell which occasionally rushed into the cove, dragging divers along with it and into each other with a clanging of tanks.
With the challenges of the dive in hand we gathered at the designated site, known as the ‘Camp Fire’, and soon realised why it was thusly named. In the middle of a ring of stones was a crate of lights, and with all the divers gathered around (each sweeping the darkness with their own lamps), it gave the darkened waters a luminous glow.
That was exactly what the dive counted on, as if there is one thing that plankton love, it’s light. Soon our beams began to pick up static-like flickers as the plankton amassed. And as already discussed, if there is one thing that mantas love (apart from other mantas of course), its plankton.
It’s pretty surreal being on the ocean floor in inky blackness at a depth of 10 metres, watching the strobe-light effects of other dive lights. Even more surreal is suddenly seeing a gigantic mouth loom out of said darkness, all-encompassing wings flapping as a manta ray swoops down upon you.
Abruptly, your world is eclipsed by a gigantic manta maw and then in a blur of white its huge body passes over you and it is gone again. Soon the ‘Camp Fire’ was surrounded by manta rays, moving at a slow but unstoppable pace, wheeling and whirling in a virtual manta ballet.
Hold your light above your head and the mantas swoop low overhead, bring your light closer to your face, and they come within a fraction of engulfing you. They came so close, you could almost hear millions of plankton scream (well, you would if plankton scream, which they don’t, although they can’t have enjoyed the experience of being eaten alive).
It was such an enthralling experience that I often found myself forgetting to breathe, as more and more mantas loomed out of the night. Occasionally one would come so close that I could see the back of its throat, or count the filaments on its gigantic gill slits.
At one point there were 15 mantas enjoying their planktonic feast right in front of us – truly an awesome sight to behold.
Unfortunately, one could also clearly see the impact of humanity on these gentle giants, as several had one of their mouthparts severed after becoming entangled in the gigantic long-lines dragged behind fishing boats.
While this incidental by-catch is bad enough on such a long-lived and slow-breeding species (they give birth to only two young after a gestation period of 12 months), even more alarming is the fact that mantas are being targeted by the scourge of wildlife throughout the world – the traditional Chinese medicine trade. Caught solely for their gill rakers, thousands of these magnificent animals are butchered every year for this trade alone.
Forty minutes passed in the blink of an eye as we all watched spell-bound by our leviathan companions. And then all too soon our dive master was gesturing us to follow and it was time to resurface.
The darkness closed around us once again, save for the beam of our torches that illuminated the occasional eel or wide-eyed cardinalfish.
Behind us, still swooping about in the fading light, the mantas continued their nightly dance.