Two fatalities in Monterey

[mdb]

It is good to see that we are now talking about weighting as well as gas management, emergency options, and other topics in this thread.

Proper weight, and weight placement, is obviously something that should be a center of focus.

In the "old days" the mantra was your body weight plus 5 lbs. when diving in a 6-7mm wetsuit in CA waters.

These days I dive with 22 lbs in a skin-two hood attached FJ wetsuit with a steel tank-50 or 80.
10 lbs on my waist, 4 lbs in each BC weight pocket and two 2lb weights on each side of the tank band.

Dack has made a very good point. Overweighting is certainly something that frequently occurs.

 

[Bubbletrubble]

Now you are probably going to think I'm a real nag, and I don't mean to be, but... do we know they were using 2400psi tanks? I know that your main point is that they had had an earlier dive, which does seem to be fact, and I understand you had some low fills on this boat in the past, but I don't think we know how much air was in their specific tanks to start off with (again, unless I have missed this) (actually, does anyone here know what type or size tanks they were even using?).

@Blue Sparkle: I do not have any firsthand knowledge what size/type tanks the victims were using.

The Monterey Express provides its dive boat customers with LP80 steel tanks. It says so on the company website. The use of such tanks is included in the price of the boat trip.

Given the fact that the group had traveled a fair distance to Monterey and the group was rather large, I think it's certainly reasonable to think that, in all likelihood, they used the dive op's tanks for the Saturday dives.

Even if the victims had been using short-filled LP80s on the fateful dive, I'm not sure how much of a contributing factor this was to the incident. Regardless of the instructional agency used, every OW certified diver I know has been trained to check his SPG prior to conducting a dive. Keeping a vigilant eye on one's SPG helps the diver determine when turn-pressure or ascent-pressure is reached. At that point, he and his buddy should be turning around or ascending (whichever was agreed upon in the pre-dive plan).

 

[Blue Sparkle]

@Blue Sparkle: I do not have any firsthand knowledge what size/type tanks the victims were using.

The Monterey Express provides its dive boat customers with LP80 steel tanks. It says so on the company website. The use of such tanks is included in the price of the boat trip.

Given the fact that the group had traveled a fair distance to Monterey and the group was rather large, I think it's certainly reasonable to think that, in all likelihood, they used the dive op's tanks for the Saturday dives.

Bubbletrubble,

I agree that it's reasonable to think that the divers in question were probably using the standard tanks from the boat. Thanks for the link to that page showing they rent LP80s.

Even if they weren't using those tanks for sure, I don't have any problem with speculating or coming up with a scenario such as "If they were using the standard LP80s that the boat rents..."

I was actually responding in the context of one of K_girl's earlier posts, which somewhat intimated that they might have been given "short" fills, and that it might have been a contributing factor. That's okay as speculation. But then it almost sounded like it had turned into "fact" when it was mentioned again in a later post (more on why this might have been my mistake at the bottom).

Here's how I got where I was going with my last post:

This was said:

I have dove off the Monterey Express for years and always had a great crew. They provide tanks or you can bring your own. When I first started diving with them in 2001, you would always get 3000 psi on steel 80s for the dives. A few years later, it went down to 2800 psi, last couple of years 2400 psi. I bring my own tanks because of it. I am not blaming the dive op for this accident. Every diver must monitor their air usage.....

... I believe that the combination of less air available in the tank, the deeper dive, which means less dive time, and the building of confidence led to these boys losing track of a reduced available dive time, their air usage and utlimately, the accident. It was reported that one boy was out of air and the other was very low.

Again, I am not blaming anyone, just pointing out what could have potentially led to the accident.

And then in a subsequent post:

the accident occurred on the second dive Saturday morning [on the Monterey Express]. So they did have one successful deeper boat dive on the 2400 psi tanks off the Monterey Express. Even though I am sure that the second dive was shallower than the first, you can actually use more air on the second dive because you are colder and fighting to stay warm.

I'm not sure if I just read this wrong, or what (and my apologies, K_girl, if I did :blush, but it seemed like there might have been an assumption that the boys were diving on underfilled tanks. And like it might have gone from supposition into "well since they were diving on..."

That's all I was pointing out. As it turns out, if they were using LP80s, I don't see that 2400 would be under-filled anyway, so maybe I just misunderstood something in this sequence, or maybe K-girl was saying that they used to overfill and no longer do? Since she said "80" and "3000psi," I wasn't initially thinking they were LP tanks.

Either way, of course they were responsible for monitoring their air supply. I just was trying to keep supposition and fact separated in my own mind, and here.

So, sorry if I raised a fuss over nothing :blush:

Blue Sparkle

 

[DandyDon]

IF they were using LP80s furnished by the Op, which would be a reasonable speculation, then 2400# would not be a short fill would it? It'd be 80cf. I see on this chart that an LP80 starts at -7# buoyancy full, ends at -1# empty which is a 6# gain but still would suggest why the kits have not floated up.

It is good to see that we are now talking about weighting as well as gas management, emergency options, and other topics in this thread.

Proper weight, and weight placement, is obviously something that should be a center of focus.

In the "old days" the mantra was your body weight plus 5 lbs. when diving in a 6-7mm wetsuit in CA waters.

These days I dive with 22 lbs in a skin-two hood attached FJ wetsuit with a steel tank-50 or 80.
10 lbs on my waist, 4 lbs in each BC weight pocket and two 2lb weights on each side of the tank band.

Dack has made a very good point. Overweighting is certainly something that frequently occurs.

I brought up that overweighting is common for newbies a day or so ago, but someone objected to my wording, and it may have been before the thread merge. It is common, especially on first ocean dives - further possible reason for the kits to be sinkers if their BCs were integrated since the rescuers took them out of their kits on recovery.

Excerpting from the official school statement: School district issues statement about students' deaths | Carson City Nevada News - Carson Now

Following successful dives on Friday evening and Saturday morning, both young men who had recently become certified scuba divers, did not surface with the rest of the group during the second dive on Saturday morning.

Diving instructors accompanying the group began searching for the divers immediately while emergency calls were made to the local fire department rescue squad and the Coast Guard. The bodies of the young men were located together on the sea floor following a 2 ½ hour search. Both air tanks of the divers were empty. Government agency officials who were on the scene consider the deaths accidental.

So they were newbies, did an evening dive the day before - which I would doubt was an actual night dive with such newbies, but now that statement is claiming a longer search.

 

[Bubbletrubble]

IF they were using LP80s furnished by the Op, which would be a reasonable speculation, then 2400# would not be a short fill would it? It'd be 80cf.

@DandyDon:
The LP80 tanks that I have used only contain the stated capacity if filled to the "+" rating, which is a 10% fill over the 2400 service pressure (2640 psi). Depending on whether the LP80 tank was made by Faber or PST, a fill to 2400 might translate into only having approx. 70 to 73 cubic feet of gas (according to the tank specs chart I like to use).

In any case, regardless of whether the victims had 70 or 80 cubic feet of gas to start with, each diver should have been aware of the starting pressure of his tank and that of his buddy's tanks before entering the water. Any "short-fill" scenario should have been discovered in plenty of time to revise the pre-dive plan.

I see on this chart that an LP80 starts at -7# buoyancy full, ends at -1# empty which is a 6# gain but still would suggest why the kits have not floated up.

Whether the gear floats up to the ocean's surface is a function of more than just the buoyancy specs of the empty tanks. It's possible that the BCDs contain enough air to make the overall system (BCD + tank + regs) positively, negatively, or neutrally buoyant. As you pointed out, we also don't know if the BCDs have some weight loaded into weight-integrated or trim pockets. There's also the possibility that the gear is positively buoyant yet is caught under/on something. If the authorities haven't been able to retrieve the victims' gear by now, there must be some issue with current/surge/tidal movement in the area that is complicating gear recovery. After all, the victims were found by rescuers at a recreational depth.

 

[MauiScubaSteve]

Haha, just noticed all the fuss as I've been fussin' with this....

I have dove off the Monterey Express for years and always had a great crew. They provide tanks or you can bring your own. When I first started diving with them in 2001, you would always get 3000 psi on steel 80s for the dives. A few years later, it went down to 2800 psi, last couple of years 2400 psi. I bring my own tanks because of it. I am not blaming the dive op for this accident. Every diver must monitor their air usage.....

....

Again, I am not blaming anyone, just pointing out what could have potentially led to the accident.

So, first let me say that in early spring '01, Ocean Divers in Key Largo replaced all of their AL80's with LP80's; I know 'cause I helped load the AL's into a box truck, headed for Cuba maybe? I heard something about a really good package price.

Scuba Cylinder Specification Chart from Huron Scuba, Ann Arbor Michigan

Faber shows a 2400 psi steel 80 and a 3180 psi steel 80 on that chart (link above); I'm assuming the 2400 is the more recent of the two. Not saying I know anything about the Monterey Express, but a good package price for new tanks that work the compressors and regs less hard is perhaps smart business.

Then you have to retrain the crew to pump to a lower pressure, and the training is like that with old dogs, and "+" means 2640 psi, but after the first Hydro some tanks are not "+" anymore.

Service pressure is service pressure, By US Regulations, a 2400 psi tank is supposed to not exceed 2400 psi, when it gets to ambient temp. How soon after pumping were your various pressure checks before?

Very hard to even bring up tank size. Do we know for sure the tanks in question? Teen age varsity football players often get a bigger tank, even here in nearly warm water Hawaii.

 

[Ben_ca]

This article below described it as "an evening dive." But this is not an important detail in the context of what I wrote in my post. There are no boats in Monterey that do "evening dives" either, so that was a shallower, shore dive.

Monterey boats do night dives. Not that often since there isn't much demand but to say that there are "no boats in Monterey that do evening/night dives" is not correct

 

[K_girl]

K_girl,

I understand what you are saying. It just concerns me when "facts" creep in with little fanfare, even when they are not the main point of a sentence. I realize that you were not trying to do this (and in fact they may have made a night dive, I don't know).

I have no problem with speculation, as long as it's clear (I have written a few "I wonder if" possible scenarios myself in this thread, and I think they can be interesting and useful).



Now you are probably going to think I'm a real nag, and I don't mean to be, but... do we know they were using 2400psi tanks? I know that your main point is that they had had an earlier dive, which does seem to be fact, and I understand you had some low fills on this boat in the past, but I don't think we know how much air was in their specific tanks to start off with (again, unless I have missed this) (actually, does anyone here know what type or size tanks they were even using?).

Blue Sparkle

Monterey Express carries only 80 steels (no other sizes), and have consistently put 2400 psi in the tanks for quite some time and they tell you that in the briefing and they warn you to pay attention to that. Since the divers were from out of town and not aware of the boat's air tank fill policy, it is highly doubtful they rented different tanks.

 

[Blue Sparkle]

K_girl,

Okay, I see that now. I guess I was just confused because in your post prior to that one, you were talking about how the boat used "80s," which they used to fill to 3000, then 2800, and then 2400 and then you started bringing your own tanks board when you dived with them. I'm sorry if I missed something.

Blue Sparkle

 

[K_girl]

Haha, just noticed all the fuss as I've been fussin' with this....



So, first let me say that in early spring '01, Ocean Divers in Key Largo replaced all of their AL80's with LP80's; I know 'cause I helped load the AL's into a box truck, headed for Cuba maybe? I heard something about a really good package price.

Scuba Cylinder Specification Chart from Huron Scuba, Ann Arbor Michigan

Faber shows a 2400 psi steel 80 and a 3180 psi steel 80 on that chart (link above); I'm assuming the 2400 is the more recent of the two. Not saying I know anything about the Monterey Express, but a good package price for new tanks that work the compressors and regs less hard is perhaps smart business.

Then you have to retrain the crew to pump to a lower pressure, and the training is like that with old dogs, and "+" means 2640 psi, but after the first Hydro some tanks are not "+" anymore.

Service pressure is service pressure, By US Regulations, a 2400 psi tank is supposed to not exceed 2400 psi, when it gets to ambient temp. How soon after pumping were your various pressure checks before?

Very hard to even bring up tank size. Do we know for sure the tanks in question? Teen age varsity football players often get a bigger tank, even here in nearly warm water Hawaii.

Nothing is "for sure" because I do not have direct information. Last time I went, I was the only one who brought my own tanks. They were steel 80s in 2001 with 3000 psi fills and then recently also steel 80s with 2400 psi fills that did not look like they were updated tanks to me. In addition, I dove two trips on the 2400 fills and did not get the kind of air usage I was used to on earlier dives with higher fills on the same boat.