Tropical fish collection, at the very least on a commercial basis, is one of the toughest jobs I have ever had. We came to Moloka'i, Hawai'i, in 1989 not knowing a guppy from a grouper. Taking fish from the wild brings with it a great responsibility. If you can swim the reef, collect what you need (no more, no less) and leave the water with minimal signs that you were there, then you are becoming a good collector. The fish you take home should show absolutely no signs of ammonia burn, no raised or missing scales or no sign of the bends. It is not easy to bring home a "perfect fish". You have to take the time to set the net correctly, don't let the fish "squirrel around" in the net and abrade their skin, don't rush decompression (for fish caught below 30 feet), and don't crowd them into a collection bucket to the point that they get burnt. In other words, take your time and do it right. Tropical fish are a precious commodity and a gift from nature and you should respect them as such.
Of course we did pick one of the worst channels in the world to work in. Our little 19 foot Rienell with a 190 hp Mercruiser I/O fit very well in between the 6 foot waves that are normal on the Kalohi Channel between Moloka'i and Lanai. The winds, in spite of what the forecasters on Oahu say, are usually 20-30 mph Trades (N.E.) with higher gusts. Moloka'i and Lanai form sort of a funnel, and the Trades usually start really kicking in and cross the channel by about 9:00 am. We even tried launching early in the morning (sunrise.....big mistake) in order to beat the wind, but found that most of the fish were keeping "banker's hours" and don't come out of their houses until the sun comes up a little later in the morning.
Mano (Hawaiian for shark) is at his finest between dusk and dawn. Humans are not normally on a shark's menu. They prefer dead or wounded stuff, but mistakes do happen. A wounded fish from spearing, or whatever, bleeds and sends out a very specific vibration that attracts predators. Fortunately, netted fish do not react this way. For the most part we were been bothered too much by sharks. In the ten years we dove and collected fish we had only six up close encounters. Statistically that's not very many, but believe me, six is plenty. There was the thing with Brutus, a 20 foot Tiger shark, but I think seeing Deb flying out of the water, tank, weight belt and all, probably scared him as much as he scared Deb. Flying fish are one thing, but flying people? It never seemed to fail, just when I thought I had convinced Deb that unless you could hear the theme music from Jaws, everything was fine and Mano was not around, one would show up and spook her again.
All joking aside, a lot of collectors carry bang sticks for protection against sharks. I have always figured that, "if your time is up, it's up". Hawaiians believe that Mano is their Aumakua(guardian god; familial ancestor spirit that would normally take the form of an animal to protect and do the bidding of the family), therefore, no problem. Works for me, Thanks Dad! When we saw a shark they seemed to be more curious than anything else. They would check us out and go on their way. When over the initial scare after you see one, they are actually magnificent animals. If a shark approaches you and keeps swimming smoothly, doesn't get its back up (arches) or start swimming "herky jerky", you'll be all right. Sharks that we have seen over the years are the Tiger, Hammerhead (twice), Whitetip, Blacktip and Gray species.
Before you start collecting anything, here are things you need to do and know about:


