Here's another diving story, one not listed above, from about 1978. We were bidding on a National Marine Fisheries Service (NMFs) project to study king mackerel or kingfish "fallout" from gillnets as they migrated around the Florida peninsula. Gillnets have a fixed net apertures, fish vary in size of course. If a fish swims into an aperture, it gets "gilled" or stuck when the net catches behind their gills. The net is pulled in and the fish are pulled out into the boat.
King Mackerel or Kingfish
From:
http://www.landbigfish.com/
If this fish is too large, as in the case of some King Mackerel, it might just get its nose stuck momentarily. This apparently sent some mackerel into something akin to a fish heart attack, killing them on the spot, they "fallout" of the net and were lost. Bycatch was and still is a serious concern related to netting, fallout was another resource depletion issue as well. It wasn't well understood at the time, hence the study was proposed.
Gillnets
From: Drifting net,
http://www.fao.org/ and Secured net,
http://www.cnsm.csulb.edu/
The Request For Proposal stated that divers using a wetsub were to document the interaction of larger king mackerel with gill nets, documenting fallout process and estimating quantities of fallout per netting run. We were also to recover fallout specimens for evaluation by NMFS. This was to be repeated around the migration along the Florida coast. As shark have trailed the migration since time began and now having strugging, dying and dead, large king mackerel around the nets boosted the risk of negative shark interactions. NMPS likely anticipated the successful bidder using something like the "Sharkhunter" popular in some areas in those days.
The Sharkhunter wetsub
From:
http://www.psubs.org/
I recall that Walter Stark formerly of RSMAS may have used one of these for studying sharks in off some Pacific atolls. This may have lent some support for using these two man subs in this application.
Well, we didn't have a Sharkhunter, but we did have a Rebikoff Remora. So, decided to construct a cage around the diver and propose using this. Talk about flight modification! As you have a power umbilical, you have the added advantage of using surface air supply, a comlink, even video feed to the surface. I seem to recall portable video cameras had yet to come out for UW use. Camera heads with surface feed were still in use. So, it presented some key advantages over the Sharkhunter and a few disadvantages as well.
The Remora closely resembled the Rebikoff Pegasus shown above
Visualize this, you are motoring in poor visibility, in cold water, in waves, variable current, mackerel are schooling thick about you with all that detritus they expel. The odd shark or pack roils through the school from time to time but largely are invisible due to poor viz. and lots of fish in the way. Then the net shows up, barely. You see struggling fish, sharks again yanking the off buffet item off the net. If you're lucky, you might even see some particularly large mackerel nose in, explode into spasms, expire and fall out of the net. If you're really lucky you be able to keep it in sight without getting netted yourself as it settles to the bottom. There you can pick it up, assuming you don't have to beat sharks off to grab your specimen. Then get the lot including yourself and your Remora safely on the rocking boat. Easy, right?
Spent a ton of time thinking this over, planning and on project design. Despite making a good bid, we didn't get it. The firm that did, never put any divers in the water, with or without a wetsub. I understand they towed a video camera with a ruler scale inset, that was the bulk of their study?! Well, they probably didn't lose any divers, then again, they never hired any in the first place. Your public dollars at work, back in the day. In hindsight, I'm thinking, well it would have been real interesting but maybe we lucked out after all in not getting the project?
A bit more about the controversy dealing with gillnetting king mackerel appears at:
http://www.thefreelibrary.com/40+Yea...g.-a0212034487
and about the mackerel migration at:
http://spo.nmfs.noaa.gov/mfr563/mfr5632.pdf
So, there's another one, see they don't even have to happen, completely. A good tale with a near miss works too. Over to you ...