Of all the possibilities that I have read not one seems highly likely, but obviously something bad happened.
As a result, I can't think of one thing that would constitute a "lessons learned" that could prevent a similar
event in the future.
I will note that I do not believe the downwelling theory. It was reported that as some point that the mom
did not see any bubbles. If she was at the top of the wall, it is possible, perhaps very likely, that she could
have taken care of personal issues, secured the camera, verified her air and deco status then looked down
to see no bubbles. In the short time she was not looking, the current just moved the bubble stream
downcurrent where they ascended out of sight. Additionally, since she was drifting northish as well, she
should have encountered the downwelling or some aspect of it.
There is one aspect that could save or recover another missing diver and that was the dive community search
and rescue operation that sprang to life. While great efforts were made on the assumption that he made it
to the surface, there was nothing that I read that confirmed that he made it to the surface. The fact that he never
rejoined with mom doesn't mean that he did not surface, but it is clearly a possibility that he did not.
Thus the massive plane and searches search were important, but it may be that the recovery aspect was not given
high enough priority. Don't take anything that follows as criticism. They are my musings on how this tragic
event can turn in to something that has great outcomes in the future.
Ideally, given adequate resources, you cover the area at the wall down as far as possible and as far north as the
person could have possibly been carried by the current. You also run a linear (with the current) grid from the
wall to the shore..again going as far north as the person might have been carried by the current. This assumes that
the person is on the bottom. If the bottom is sloping like at one or more of the Palancar sites, the person might
be found. If the wall is closer to vertical with the bottom beyond reasonable search then you accept that reality.
A surface search using boats would be conducted also using a linear grid. The lead boat might be along the wall
or other suitable reference. One or two boats could be towards open water a suitable distance from the lead
boat and the majority of the boats are distributed towards shore. I am not a boat person so some things may need to
change. Personally, I would have boats arranged in a V formation so all boat captains can see and maintain lateral
spacing with the lead boat. Three or more observers on each boat look forward, left and right (port/starboard).
Knowing the currents you continue to a point perhaps two miles past where the person would be located on the
surface using worst case surface or deeper currents.
During this process you drop two buoys with a trackable Spot on them. One near the disappearance point and
one near where the person would be expected to be on the surface. These would aid in plane searches.
The boat surface search and trackable buoy can be practiced in a non-emergency manner to refine techniques
and get a large enough trained cadre of boat assets that a rapid search can be started when needed. Many things will
become apparent and resolved as you practice. One thing is how to record where you have searched. On boats,
you can have GPS units that record the path taken. Somehow that is recorded at the command center. The same
applies to the underwater searches but may just be dropoff and surface pickup locations with lines on a computer
map program or as simple as grease pencils lines on plastic over a map.
This capability will be needed again. Too many divers go missing and a Cozumel dive op SAR capability as suggested
by someone might be the difference between rescue or recovery or a forever missing diver.
As for divers, consider whether you need a Personal Locator Beacon (PLB), Surface Marker Buoy (SMB), mirror,
dye pack etc.
I am a believe in rescue diver training but if you and your normal buddy can't do that, get additional practice
bringing a non-cooperative diver up some safe distance. Talk to an instructor at home or see if you can get that
practice on an instructor supervised dive in the ocean.
