Back Roll Entry Head Injury

[boulderjohn]

Given that I'm not mentally defective, i think I have a pretty good handle on what happened

I should have mentioned in my last post that I was not suggesting that you are mentally defective not that you do not know what happened in this case. What I meant and what was made even more clear in your following post is that you don't have much experience with the kind of entries being described. You are making some guesses that are not accurate, and it might be a good idea to avoid attacking people for following protocols that are done quite literally thousands of times a day without incident because they do not look like the protocols with which you are more familiar.

 

[djcheburashka]

No, I know exactly what happened in this case because it is completely obvious. It is a basic fundamental mistake on entry technique. It's not like this is a rare error. There's no mystery here. And back entries in Cozumel are not different from back entries in Miami, New York, Thailand, or anyplace else.

 

[boulderjohn]

If you are even thinking that a slow controlled ascent from 2 feet of depth is what happens on a back entry, then you are doing it completely wrong. Unless your wing is highly positive on the entry, you're going to hit at least 10 feet. That's where you regain control and ascend.

The fact that you were talking about it this way, in terms of only dropping 2 feet and then immediately popping to the surface, says that you do not know the maneuver. Entering like you described creates a nontrivial risk of injury from the boat or other divers.

I don't know the maneuver? I don't know how many hundreds of students I have watched do this in a swimming pool during their training. The pool is 11 feet deep, and they do not go anywhere remotely close to the bottom. I have never in my life seen anyone go to 10 feet on a back roll and then do a slow ascent to the surface. Why on Earth would you do that?

 

[djcheburashka]

When people do their basic open water training in the pool, it's true they don't hit 10 feet. Because they aren't falling very far. But A Diver doing a back entry has to hit at least enough depth to clear the bottom of the boat.

And yes, you're doing it wrong.

---------- Post added June 25th, 2014 at 04:49 PM ----------

The answer to "why would you do that" is that it would be better to simply descend, but if UR meeting people on the surface then an ascent is how you get there. And changing your depth has to be under control

 

[boulderjohn]

When people do their basic open water training in the pool, it's true they don't hit 10 feet. Because they aren't falling very far. But A Diver doing a back entry has to hit at least enough depth to clear the bottom of the boat.

And yes, you're doing it wrong.

I have no idea what it means to "hit at least enough depth to clear the bottom of the boat." If you mean (????) it is necessary to go deeper than the depth of the bottom of the boat, does that mean that you think the small boats people are doing back rolls off of in Cozumel have 10 feet below the waterline?

You may have missed the statement that this is a buoyant entry. If you are properly weighted and have air in your BCD with the goal of floating on the surface with it when you are done, you cannot go down more than a few feet from the momentum of your fall without a lot of hard kicking.

As for everyone else doing it wrong, as I said, in Cozumel alone there must be many hundreds of back roll entries such as I describe done every day. I have dived in many places around the world, and I have seen it done that way in many of them. I had to do it that way for my instructor training class, or I would not have passed. So, if I am doing it wrong, I am in good company.

 

[djcheburashka]

By clear the boat I mean that when you stabilize you're deeper than the bottom of the boat. Otherwise you stand a good chance of it hitting you or you it in the waves.

It *isnt* a bouyant entry, it's a negative entry. The op's accident demonstrates the risk of doing it as you propose.

And you may well be in good company--it's a common mistake, but a mistake nevertheless!

 

[boulderjohn]

It *isnt* a bouyant entry, it's a negative entry. The op's accident demonstrates the risk of doing it as you propose.

And you may well be in good company--it's a common mistake, but a mistake nevertheless!

Here was my first reply to you:

While I prefer a negative entry myself, the boat crew makes the decision. Most of the times in my experience in places like Cozumel it is a positive entry, with the group getting together on the surface and then descending.

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.

 

[azscubadude]

You are very lucky, it could have been much worse.

The worst Scuba Diving accident I have ever seen happened on my very first trip to Cozumel in 1990.

We were diving on a small boat and doing bankrolls off the side. The crew was vigilant in that they watched the divers bankroll off the side one at a time. They watched to make sure as each divers bankrolled in and was clear before letting the next diver roll off.

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.

The crewman, not knowing she went under the boat, signaled the guy on the opposite side of the boat to roll off and into the water. As soon as he rolled off the side the woman diver cleared the underside of the boat. At the very split second he hit the water the woman diver cleared the underside of the boat and ended up directly underneath him. His tank caught her square in the head and split it wide open. She was out cold in the water and there was blood everywhere. It took everyone to get her back on the boat. The captain radioed in and an ambulance met us at the dock of one of the southern resorts. She never regained consciousness during the whole episode of getting her back on the boat and to the waiting ambulance.

It was a terrible terrible accident that came close to killing her. She never came back to the hotel so I'm not sure what happened but from what I saw it couldn't have ended very good. You could tell by the wound and all the blood that her skull was cracked wide open. It was not a pretty picture to say the least.

I have never forgotten this and always.. ALWAYS make sure that as soon as I hit the water I am finning backwards to get as far away from the boat as possible before the next diver rolls in.

 

[dumpsterDiver]

You are very lucky, it could have been much worse.

The worst Scuba Diving accident I have ever seen happened on my very first trip to Cozumel in 1990.

We were diving on a small boat and doing bankrolls off the side. The crew was vigilant in that they watched the divers bankroll off the side one at a time. They watched to make sure as each divers bankrolled in and was clear before letting the next diver roll off.

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.

The crewman, not knowing she went under the boat, signaled the guy on the opposite side of the boat to roll off and into the water. As soon as he rolled off the side the woman diver cleared the underside of the boat. At the very split second he hit the water the woman diver cleared the underside of the boat and ended up directly underneath him. His tank caught her square in the head and split it wide open. She was out cold in the water and there was blood everywhere. It took everyone to get her back on the boat. The captain radioed in and an ambulance met us at the dock of one of the southern resorts. She never regained consciousness during the whole episode of getting her back on the boat and to the waiting ambulance.

It was a terrible terrible accident that came close to killing her. She never came back to the hotel so I'm not sure what happened but from what I saw it couldn't have ended very good. You could tell by the wound and all the blood that her skull was cracked wide open. It was not a pretty picture to say the least.

I have never forgotten this and always.. ALWAYS make sure that as soon as I hit the water I am finning backwards to get as far away from the boat as possible before the next diver rolls in.

i just hate this.. when people give real world experiences about accidents they have seen and we all know that nothing like this could happen.. Many thousands of people do this every day. If it was a dangerous procedure, it would never be done. You just need to trust the crew and roll when they say. there is no need to use a procedure that allows you to be reasonably sure you will not land on anyone..

 

[T.C.]

It was a terrible terrible accident that came close to killing her. She never came back to the hotel so I'm not sure what happened but from what I saw it couldn't have ended very good. You could tell by the wound and all the blood that her skull was cracked wide open. It was not a pretty picture to say the least.

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.