Missing Diver - Grand Cayman Sept 21, 2009

[Rick Murchison]

...the Dive Industry IS an Industry...

Be very careful with your words...
Lurch's first law of laws says

"Never evaluate a law by its intent, but rather consider how it can be used by the most evil, greedy, rapacious power hungry bully in existence, for that is how it will eventually be used, and by whom."

The next thing you know we'll have folks talking about industrial accidents, and OSHA bureaucrats descending on us like a turd off a tall buffalo!

Rick

 

[bowlofpetunias]

Be very careful with your words...
Lurch's first law of laws says
The next thing you know we'll have folks talking about industrial accidents, and OSHA bureaucrats descending on us like a turd off a tall buffalo!

Rick

Oops too late for that here in OZ

 

[ScubaSteve]

.........and OSHA bureaucrats descending on us like a turd off a tall buffalo!

Rick

 

[-hh]

A few statistics to sprinkle in with the speculation.

The Cayman Islands Emergency Communications Centre (9-1-1) maintains a publically accessible log of the basic details of all calls. Only calls for assistance routed through the 9-1-1 center would show up in these statistics.

Thanks for this resource. Doing a quick look, it appears to cover Cayman Brac and Little Cayman, but I am honestly extremely surprised at how few listings there are. I'll have to see if their archives cover specific dates where I've personally witnessed ambulances at the pier to cross-walk it for completeness of reporting (eg, 911 bypassed because Dive Op called Hospital directly, etc).

From January 1, 2009 to Sept 29, 2009 at 14:43 the log shows twenty reports in the category of EMS-Drowning/Diving Accident. That is at least a starting point.

Based upon what numbers are available, it seems that 50 ambulance call per year is too high a guesstimate but approximately 10-12 fatalites per year related to watersports in general may be in the right range.

Yes, its a starting point. My "calls" number is based on a former Brac dive operator who told me awhile back that the Brac typically called for a dive-medical around 1x/month. Over the past 20 years' worth of visits and witnessing of accidents, I'd say that this is about right. From there, I simply assumed Little to be calling at about the same frequency rate as the Brac and then that Grand had to be more than the two Sister Islands combined ... all simply based on gross number of diveboats operating ... and that's where I was getting my baseline estimate from.

Moving right along to speculation...

The dive site in question is near the Main Channel where the North Sound connects to the open sea. Rarely there is some current or even downwelling ... In fairness, there is not normally much current, if any, in this area.

A good observational point, as there have been accidents in Cozumel due to wall/current/tide interactions causing divers to get taken deep in "downdraft" (current down-welling) incidents. A decade (or so) ago, merely to claim their existence was a hotly disputed topic on some newsgroups...today, we know better.

We do not have information that the proximity of the wall had anything to do with this incident.

Directly, agreed.

But indirectly, we do know that because it was reportedly a wall dive, the drop-off was within some reasonable proximity, and this observation is validated by the report of a deep search also being performed.

I'm not trying to 'blame' the wall - its just the observation that very deep water makes a body recovery from it much more difficult. This makes it an area where searchers have not been able to operate, so the search pattern was incomplete.

This doesn't attribute the wall as a factor in the loss, but attributes the wall (depth topology) as a factor in the subsequent search operation's lack of success in finding the diver.

Hope this clarifies.


-hh

 

[SCUBA482]

If I may speculate a tad more, since this was a "wall" dive, and there was little possibility of a down current due to location, but what should a newbie diver like myself do should I ever find myself entering a down current near a wall? Will my ability to kick up with inflating my bc a little offset this down current or has anybody experienced a down current strong enough to overcome this? Hope I'm not too far off topic, but a speculation prompted my curiousity on the subject? Also, not put off at all as a new diver by anything on this thread.

 

[divengolf]

Here's a dive canister:

Fastfind Dive Canister

designed to hold this EPIRB:

McMurdo FastFind Max G PLB 406 EPIRB

$824 altogether and a bit heavy to travel with.

There's a much cheaper option: McMurdo Fast Find 210 PLB, introduced earlier this year, sells for about $300 as I recall plus a OMS canister #298 for about $50. You'll have to rig a harness for the canister. I'm having one made to attach to my tank bands so it will sit just behind my wing. I believe the canister is good to about 3-400 feet. I recomend the FF210 since it has GPS. The FF200 does not have the GPS incorporated in it.

Make sure that you register it with NOAA(??). The instructions come with it.

 

[Ayisha]

If I may speculate a tad more, since this was a "wall" dive, and there was little possibility of a down current due to location, but what should a newbie diver like myself do should I ever find myself entering a down current near a wall? Will my ability to kick up with inflating my bc a little offset this down current or has anybody experienced a down current strong enough to overcome this? Hope I'm not too far off topic, but a speculation prompted my curiousity on the subject?...

Search for threads about downcurrents or downwellings and you will find some excellent info on this board about how to avoid a downcurrent or get out of it if you get caught in one. Diving too close to a wall on a drift dive should be avoided and you should be watchful of the movement of particles in front of you as they flow with the current or converge with another current.

Inflating your BC and/or kicking up will have little effect in a downcurrent. They tend to be narrow columns of downward water right near a wall, so you want to swim away from the wall as quickly as possible while inflating your BC, to get out of the downcurrent. Look at the threads for more info and discussion on downcurrents.

 

[DCBC]

If I may speculate a tad more, since this was a "wall" dive, and there was little possibility of a down current due to location, but what should a newbie diver like myself do should I ever find myself entering a down current near a wall? Will my ability to kick up with inflating my bc a little offset this down current or has anybody experienced a down current strong enough to overcome this? Hope I'm not too far off topic, but a speculation prompted my curiousity on the subject? Also, not put off at all as a new diver by anything on this thread.

It depends on the down current; some can only be overcome by buoyancy. I love to dive walls and have been in a strong down current several times. I use a large wing so I've never had much of a problem, but the first time it happens to you it's an eye opener.

There's no hard and fast rule when it comes to down currents. The best defense is a good offense; be prepared! I watch the wall to watch for any shifts in the current. Generally fish will face into the current when its running. In a down current however, even large fish will be taken for a ride...

There's different schools of thought on overcoming down currents. Some say low volume BCs are better because they provide less surface area to be affected. Another group (which I agree with) is to provide greater lift to counteract the downward force and be ready to dump the buoyancy when necessary.

Some believe that it's best to hug the wall. I've noticed that if I'm away from the wall the current forces often dissipate, but you have to judge each situation as it presents itself. Being away from the wall can cause you disorientation in deep water. If you're experienced; it's not a problem, but if not, perhaps you should hug the wall.

One advantage of hugging the wall is that you can climb up or to the side. Obviously you don't want to do damage to the reef, but you may not have another option.

Generally the current will vary somewhat in velocity. When it's weaker move, when it's strong hold on.

Nitrox can also be a problem, so I never use it on walls (I often dive deep, so it's really not a gas I use often anyway).

If all else fails, remember your weight belt. Obviously drop your belt as a last resort, but keep this as an option. Personally I'd much rather deal with DCS afterwards than not make it to the surface.

Cold up currents can also be a problem, but that's another story... Dive safe!

 

[DamselDiver]

What was the tide doing? On an outgoing tide you can have incredible current flowing down the wall, on an incoming tide the current will be coming up over the wall. Inexperienced divers can be caught by surprise, also depth can be really misleading on a wall, 200' looks the same as 90' in clear water. Whenever I'm diving a wall, I'm constantly checking my depth and sometimes I'm still caught by surprise, the vertical surface is extremely misleading. I'm surprised that there aren't more accidents with inexperienced divers on these extremely advanced dives.

Safe Diving
Cheryl

 

[bowlofpetunias]

Thanks for the info on Walldives and currents... proof that the speculating in this thread leads to valuable information being shared!