Back Roll Entry Head Injury

[boulderjohn]

On one of our dives a woman diver rolled in but rather than coming up to the surface and giving the "ok" signal or finning away from the boat.. she ended up going with the current and went under the boat.

It might be an incident like that which leads Cozumel dive operators to require positive entries, so that divers do go to the surface and do not go under the boat and come up where they are least suspected.

---------- Post added June 25th, 2014 at 06:21 PM ----------

Dumpster Diver:

You have the opportunity to change diving for the better right now. What I ask for you to do is pretend you are a dive operator in Cozumel. You are in a situation where the current changes and may be different from the water movement on the surface, meaning it may be necessary for the DM to enter the water to check it out first to make sure people are being dropped in the correct location. You have surface water movement. You need to drop 6 people off of a small boat so that they can get together quickly and descend as a group. They have a wide variety of abilities. Some are on their first dive trip. Some have 200 dives. You need to use a back roll entry.

What is your procedure? What do you tell the people to do?

Remember, if you propose something superior to what all the operators there are doing now, you will be doing a great service.

 

[MMM]

Tell you what. I am down here in Cozumel diving right now. I do my back rolls without ANY air in my BCD. However I have a 3mm full suit and a 3 mm hooded vest underneath. So I'm pretty buoyant. I will try and look at my computer to see how deep I get before I "pop" back to the surface while everyone collects their cameras, new divers make sure they have enough lead, and we descend.

For the past couple of days I have been diving with a different dive OP than I perenially do. This one has been sending the DM into the water first and then divers into the water one by one, alternating from either side of the boat. It takes considerably longer than the entry I described earlier in the thread and consequently, divers are more spread out. Not a huge problem if Vis is good but it makes divers spread further apart from their buddy or the DM should assistance be needed. Of the two, here in Cozumel, I think the back roll all together is my preference...provided everyone goes together and knows that if they don't they need to stay on the boat until told they may enter the water.

 

[azscubadude]

Highly, Highly unlikely to have been very serious. It probably stunned her for a little bit, but it most certainly did not "crack her skull wide open". People who don't deal with injuries alot think that blood equals serious harm. It doesn't.

The head and scalp have some of the most numerous blood vessels in the skin. You can easily cause a very bloody wound with a few minor cuts to the scalp. Blood will be everywhere, it will look horrible...and it's all from just a few skin cuts. Anyone with emergency medical training will tell you that you ignore the bloody head wounds and look for more serious wounds- which will not be seriously bleeding, and hard to see. You can come back and put band-aids on these cuts later- that's all the treatment that is usually needed.

So, this wasn't as serious as you thought. Second- it took "everyone" to get her into the boat? Did anyone think of taking off her gear? It only takes one or two people to lift an injuried person.

I'm sorry, I didn't realize you were there.

Only an idiot would state that a 175 to 200 pound man (plus all his equipment, weights and tank) dropping approx 4 feet and striking someone directly on the head (with the tank) would not result in a serious injury.. only requiring a few bandaids.

Second- Your comment on lifting her out of the water is equally as idiotic. Do you know how much she weighed (without her gear) ??

Sometimes I wonder why I even post to this forum anymore !!!

 

[kduffy]

Diving from our deck boat, the side doors allow a pretty decent seated back roll entry with only a foot or so of drop into the water. It is important to note that the door against the padded seat does have a tendency to be pushed somewhat closed. This feature caught my wife off guard, by the fin, tucked not so nicely under the closing door and left her hanging by a leg, injuring a knee. In the inland lakes that we dive, trees and other underwater obstructions are often seen dependent on water level. It is imperative to look before rolling in.

We often use tethers to hold our gear near the boat and enter the murky water before getting in the pre-rigged BCD. It is easier and safer in our case, and the tethers hang waiting for use when getting back on in a reverse fashion. It is time consuming, but not air consuming, and we are out for fun not efficiency.

When on the pontoon, a giant stride is as likely to be used as the tethers. It is only a few steps from a seat or bench used to gear up, to a gate and it has a flat deck like stepping of a dock. Situations vary greatly. Everyone needs to have a varied experience to and willingness to learn new things.

I thought this thread could use a change of direction.

 

[dumpsterDiver]

It might be an incident like that which leads Cozumel dive operators to require positive entries, so that divers do go to the surface and do not go under the boat and come up where they are least suspected.

---------- Post added June 25th, 2014 at 06:21 PM ----------

Dumpster Diver:

You have the opportunity to change diving for the better right now. What I ask for you to do is pretend you are a dive operator in Cozumel. You are in a situation where the current changes and may be different from the water movement on the surface, meaning it may be necessary for the DM to enter the water to check it out first to make sure people are being dropped in the correct location. You have surface water movement. You need to drop 6 people off of a small boat so that they can get together quickly and descend as a group. They have a wide variety of abilities. Some are on their first dive trip. Some have 200 dives. You need to use a back roll entry.

What is your procedure? What do you tell the people to do?

Remember, if you propose something superior to what all the operators there are doing now, you will be doing a great service.

I can not devise the system I would use until I understand the situation. What does the DM have to do with this entry? Why can't the captain not use his GPS, knowledge of the wind drift and determine the velocity of the surface current? How deep and how long does the DM have to dive to determine the velocity profile in the water column? I have dropped people off boats in currents MUCH stronger than cozumel many hundreds of times..

I have already given precise description of the method I prefer to use, but it does not involve a DM entering the water before hand.

 

[Don Quixote]

Hi,

Have done a lot of back roll entry from dinghies. It has to be all divers at the same time, "1, 2, 3, go!" Have one person hit in the head like what happened to you in a dive in Bali. The main reason is the guy sitting next to him rolled over late. So, might be wise to get a feel of the person next to you, like he is also ready to roll with his hand on his mask instead of still fixing things. And, maybe shout out to the DM telling that the group is not ready, 'better safe than sorry.'

Hands - one on the mask and the other at the back of your head to keep the strap.

Feet - knees close together until you're in the water. This will prevent injuries to your thighs and legs on some boats (bangkas) that have a narrow seat gap.

BCD - deflated (negative) or inflated (positive) as instructed by the DM. So, always ask and check in advance. Deflated (negative) entry may not be easy for novice divers who have poor buoyancy control or are over-weighted. But all the back roll entries I had are negative entry.

Position - Torso leaning forward with back of knees as close to the seat corner as possible. This will prevent bruise to your calf.

1, 2, 3, Go!

I ask and learn from the instructors who have a lot more experience than I do.

- Don Quixote

Background:

I was on a boat in Cozumel with 9 divers, the DM and the boat captain. The boat had no capability for giant stride entry, so back rolls were required (common for Cozumel 6 packs). .............................

 

[djcheburashka]

Here was my first reply to you:


So all along I have been describing a buoyant entry, as I clearly said, and you have been describing a negative entry. I know what a negative entry is like. That is not how they do it there. That is not how they do it in most of the places I have dived.

So let's go back to what in that quote. I said I prefer a negative entry, but you have to follow the policy of the boat, and in Cozumel they prefer it differently. Notice that I point out that there are different ways to do it, and there are reasons for those differences.

Now lets see what you have to say. You say there is only one way to do it, and everything else is wrong. Everything taught in courses around the world is wrong. Everything done in dive locations around the world every day is wrong. Only the way you do it is right, and the rest of the world is ignorant and wrong.

I have to admit, I greatly admire such courage of conviction. Put in the situation in which I discover that so many of thousands of people with so much more experience than I have are doing something differently from the way I do it, I would play the coward role and try to find out the reasoning rather than pronounce them ignorant and wrong. I guess it's a personal weakness of mine.

Continuing to do the same thing again and again that doesn't work is the definition of insanity. This thread is about someone doing exactly what you describe who experienced exactly the injury that I said is a risk of doing what you describe.

It certainly makes sense to try to do an entry that's close to neutral with a *little* air in the bc.

I'm sorry, but I took the same class you teach, and it was pretty clear when I learned it not to do exactly what you describe.

There are two possibilities: one is that lots of people and agencies have decided the right thing to do is something dangerous that makes no sense. The other is that you have a subtle misperception of what people are supposed to be doing, and there are a number of divers who do the same thing because they lack experience and have buoyancy problems.

Tonight I watched the instructor on tonight's trip give a direction to her class about inflation on the back entry. I listened closely because of this discussion. What she said was "remember to put a *little* air in your bc." That makes sense to advise beginning divers so they don't start the class so negative they can't recover. I suspect that's what was intended in your instructor training.

But having divers outside a class, who are supposed to be capable of diving unsupervised adjust their gear so it poses an immediate danger on entry, like the op experienced, makes no sense at all.

 

[DandyDon]

Everyone else may to a positive entry in Cozumel, I don't know, haven't asked or looked - but I do a negative. I don't surface until the end of the dive usually, just meet the others at 10-15 ft.

Let me share my ignorance. I am not very experienced -- less than 50 dives. I understand the need for everyone to stick together, and I understand how they are trying to do it. But it seems like there's a better way that's been alluded two once or twice.

Why not have people enter the water in a fairly controlled manner (one or two at a time) and then have them hang onto a trailing line until everyone is in the water? Everyone can get in, do a last-last equipment checkup, fix anything that needs fixing, and then all descend together.

This seems obvious. There must be a reason it's not SOP.

Yep, there is. Cozumel boats are often drifting with current at the time so the divers need to enter together, then get down quickly. Your way, and they'd be off of the site by the time they finished.

Sorry, I am traveling, did Death Valley after 4 hours of sleep after 20+ hours of traveling, so I am just not up to reading all the posts since Monday.

 

[CarlGH]

First, let me say that I'm glad that you are ok and not badly hurt. You should definitely have seen a doctor on Cozumel, if only to have applied the butterfly bandages. We have a doctor's name that we used a few years ago when our kids were younger. He used to visit the club we stay at (Occidental Allegro) on a regular basis, but only comes when needed these days (the club is a different story - I will post on that later.

Even when i have them hand me my camera I roll out and away from the boat, then swim a bit back to the boat so they hand me my camera. I never roll with hit as such hits can dislodge some of the seals on the strobes or other lights, although on my new housing (Nauticam / Olympus EM-1) pretty much guarantees that he housing won't be breached in a maneuver like that. Still I'd rather not have water get into one of the YS-D1 strobes or the L&M Sola 1200 light head if it hits the water wrong (not that I think it will, but I prefer the extra precaution).

 

[MMM]

Tell you what. I am down here in Cozumel diving right now. I do my back rolls without ANY air in my BCD. However I have a 3mm full suit and a 3 mm hooded vest underneath. So I'm pretty buoyant. I will try and look at my computer to see how deep I get before I "pop" back to the surface while everyone collects their cameras, new divers make sure they have enough lead, and we descend.

For the person worrying about uncontrolled ascents with back roll entries, I watched my computer today as I back rolled in. My computer doesn't begin to show depth at the beginning of a dive until you reach 4 feet. Since it didn't register a depth, I have to assume that I am descending less than 4feet on the roll. Eyeballing the distance when I looked up, I would say it was more like three. So I won't worry about my "uncontrolled ascent" from that depth. To hit 10 feet or more, from a back roll off a six pack, I would need to be GROSSLY overweighted. Come down and try it for yourself!