My thinking is, if you can find a place where the sharks are feeding naturally and you can plop yourself down in the middle of it to watch, then why not. If you have to introduce providing food into the mix to attract them to a spot, then you're talking interference.
The mantas had been feeding outside of the now Sheraton for years before the manta dive began, if anything it was the hotel lights creating the feeding station. When they disappeared for about 4 months back in June of '99 it was a bummer... for some reason the mantas had decided to feed elsewhere. In August of that year a couple of my co-workers were leading a dive up at Pipedream off Keahole point in the late afternoon and noticed mantas heading into the bay. I recall them telling our boss he's got to send a boat up there one night to see if they're feeding there. He didn't, so one of them started telling other operators that they'd seen mantas heading towards the cove in the evening. A couple weeks later Eco Adventures didn't show up at the Sheraton site on their usual nights and word got out around town from their customers that they'd found a "secret manta spot". Everyone figured it out real fast. They come and go, disappearing every now and then, they've been found feeding in good numbers further north a few occasions during the day when they haven't been at the cove. They're gonna eat whether the divers are there or not.
Anyway, if it were a matter of dive companies flat out establishing an un-natural feeding behavior at a convenient spot, they'd have set it up at Turtle Pinnacle... 300 yards from the harbor, 3 pre-existing moorings (I'm pretty sure Garden Eel Cove just had 2 back in '99), a decent sized sand patch or two to set up in, able to see the water/surf conditions without even starting the boat engines. The mantas have likely been feeding at the Garden Eel Cove site for ages. It's a naturally plankton rich site, the divers aren't making plankton or bringing in outside food sources to the site, it's already there.
Tough call. Are the divers creating the condions for group feeding, or are the mantas doing it anyway and the divers are just taking advantage of that to watch? Gonna take science, guesswork, and perhaps some arbitrary moral judgements to decide that.
