Was this a terrible idea, or merely a bad idea?

[MXGratefulDiver]

A 110 fsw dive in crystal clear warm water? - yeah, piece of cake. Now a 110 fsw dive in cold, dark and green water - no

How does the water temperature or clarity change the effects of pressure on your body? Or your air consumption rate? Or your knowledge of and ability to manage mistakes or unexpected circumstances?

Diving in crystal clear water is much easier in some respects ... like keeping track of your dive buddy. It tends to reduce the cumulative effects of narcosis, although that's more psychological than physical. And warm water means less equipment to manage and compensate for in terms of weight distribution. But the trade-off is that it tends to give you a sense of security that may not be warranted. And it makes it harder to use visual clues like reduced lighting to provide feedback that you are deeper than you intended to be.

There are always trade-offs ... the key to a good dive plan is understanding them and preparing for what might go wrong. I don't see a lot of indication in the OP to suggest that was the case ...

... Bob (Grateful Diver)

 

[CuzzA]

I knew some divers who "chased narcosis" by diving to over 200 feet on air. I lost touch with them after one of them ran out of air at 210 feet (too narced to remember to look at his gauges). He did a very rapid ascent to 60 feet, where he attempted to switch to his deco gas. Unfortunately he was ascending so fast he reached the surface before he managed to make the switch. Luckily he surfaced in front of an oncoming water taxi, and instead of running him over they picked him out of the water and arranged a rapid transport to the local chamber. Unluckily, he was bent so badly he'll never again get to experience narcosis at 200 feet ... or any depth below the surface, for that matter. Last I heard from him he was physically impaired and partially blind. No idea what happened to his friends ... if they're still diving, they're keeping a much lower profile about it than they used to.

... Bob (Grateful Diver)

Good reminder that there's nothing down there worth dying or becoming disabled for. Especially just to get high.

 

[TONY CHANEY]

I'm sorry. Do we have a history I don't know about? If we do, I don't remember it at all. I don't hold grudges, not even small ones.

I asked you a question based on this statement:

No more and no less than a mere question based on nothing else but this comment. If he was diving tables, then a square profile is in order. However, most divers and even new divers nowadays dive PDCs. I can't remember when I saw the last table on a boat. My assumption is probably more likely than your assumption to the contrary. Back to the question: You're complaining about "fuzzy numbers" and so the idea that a "new diver" has to dive tables or a PDC differently than a veteran puzzles me. There's no sliding scale for the NDL based on experience on either a table or a PDC.
Wow. Where did I do that? He was diving with the shop on an "adventure dive", which means his guide was an instructor. It's nothing short of a training dive in that regard.

It's my experience that every dive site presents different challenges. A 110 foot dive on this wreck in Roatan is nothing like a 110 ft dive on the Spiegel Grove in Florida. You can call it "stupid fuzzy numbers" all you want, but the propensity for being severely narced on the Grove is significantly higher. Why is that? High currents, colder temps, darkness and stress levels are significant triggers for narcosis and the Grove has that wreck in Roatan all beat in those categories. I write this out of experience and not mere conjecture.

So, I'm sorry I don't live up to your expectations as an instructor. I'm sorry you feel there's some animosity between us that I'm unaware of. This is a discussion forum, and I'm sorry if my continuing the discussion has offended you in any way. I do believe that the dive he went on was well within his purview as a student under the supervision of an instructor/dive master. I also believe that NDLs apply the same to newbies and veterans alike. If you're diving a PDC, use the tool as intended... as you learned it.

Sorry but I was off base here. He now tells us that he was diving with a PDC. He posted this thread because he knew it was not right. I thought the he and his buddy were diving with a eRDP or maybe even tables which are not outside the rim of newly certified divers. I thought that you were picking at me from our back and forth discussion on you trip to cave country pertaining to your SM discussion. I still do not believe that dive should be judged on vis and temp but rather on depth and time. I would not encourage anyone with 4 open water dives in class to advance to 110'.
I would still dive with you and we can agree to disagree. No hard feelings on my part.

 

[The Chairman]

How does the water temperature or clarity change the effects of pressure on your body? Or your air consumption rate?

Bob, the effects can be considerable. Stress always causes us to consume more air. Any kind of stress. Dark, cold, currents and so forth will precipitate anxiety which results in a higher than normal respiratory rate. As for it's effects on narcosis, they are also documented that cold and dark can amplify the feelings of narcosis, especially if it's a dark narc that increases anxiety and of course that will affect our respiration rate as well.

Or your knowledge of and ability to manage mistakes or unexpected circumstances?

I'll give you that point, excepting that an increase in the effects of narcosis will make you "stupider" as a student once toid me.

He now tells us that he was diving with a PDC.

Like I posted, the PDC has become quite ubiquitous. I just can't remember the last diver I saw without one on their wrist.

I would not encourage anyone with 4 open water dives in class to advance to 110'.

With an instructor? On that specific wreck? Sure. I would tell them to have a ball.

I would still dive with you and we can agree to disagree. No hard feelings on my part.

I hope to be up in cave country soon, with my new Transit 350.

 

[george_austin]

@NWGratefulDiver - the OP has just gotten certified. He has not even close to the level of experience to do a relatively deep dive in challenging conditions. Currents, Kelp, cold, dark water with 5 ft or 10 ft vis adds a ton of anxiety.
This is what I've seen for over 40 years diving in Southern California with new divers or people that vacation dive only and wanting to dive here - and that's just one example.

Frankly, I'm really surprised you'd be talking about "pressure changes" WTF does that even mean? The OP has, what 20 dives?

 

[MXGratefulDiver]

@NWGratefulDiver - the OP has just gotten certified. He has not even close to the level of experience to do a relatively deep dive in challenging conditions. Currents, Kelp, cold, dark water with 5 ft or 10 ft vis adds a ton of anxiety.
This is what I've seen for over 40 years diving in Southern California with new divers or people that vacation dive only and wanting to dive here - and that's just one example.

Frankly, I'm really surprised you'd be talking about "pressure changes" WTF does that even mean? The OP has, what 20 dives?

Hopefully he learned about the effects of pressure on his body during his OW class ... I certainly did, not to mention teaching it to OW students for a dozen years.

The OP stated he did this dive directly after completing OW class. Several in here ... some of whom surprise me ... have told him that it was an OK decision. I'm not sure I agree ... frankly I think it's OK as long as nothing goes wrong. But with his level of experience, I doubt he's sufficiently equipped to deal with something as simple as a misplaced mask or an unexpected regulator freeflow ... or anything that would require him to make an ascent while holding onto his dive buddy. Sure, he learned about these things during his OW training (I hope), but he did so at a depth that made a bailout to the surface more feasible should the response not go as planned. That's not really a viable option from 100+ feet.

We don't ... or shouldn't ... plan our dives around the assumption that nothing can or will go wrong. And we certainly shouldn't plan it around relying on someone else's advice that "it will be OK" ... I co-wrote an article about that a few years back that some might find instructive ...

Don't Worry - It Will Be OK - ScubaBoard

I'll repost the final paragraph here, because I think it applies equally to this situation ...

For the new diver, you need to be less trusting of other opinions and more reliant on your own. If you’ve never experienced something before, don’t assume that it’ll be okay to get that experience in the company of someone else who has also never experienced it. If it feels wrong – it probably is wrong. Take responsibility for your dive. You are the person who is primarily responsible for your safety. Whenever you get a feeling that something about the dive isn’t right, listen to your feeling … it’s trying to keep you alive. A good adage to live by is that problems on the surface never get any better once you go underwater.

In effect, if you feel the need to ask if it's a good idea, it probably isn't ...

... Bob (Grateful Diver)

 

[Nation of Heat]

Once again, thanks to everyone who has weighed in. I've gotten what I had hoped to get in posting this topic....a much more informed perspective on how to approach decisions like this going forward. I fully expected to get get flamed a bit given the topic, but even those who thought it was an incredibly poor decision were constructive and helpful with their comments. As we all know that can be a bit of a rarity in internet-forum-world, so it was a pleasant surprise. Grateful to have found this site....I've got lots of reading to do in advance of my trip next month.

 

[beester]

First of all I want to congratulate the OP to come out in the open with his story. I think a lot of newly certified divers will have the same experience as the OP, meaning they are asked to join a dive which they know is reasonably outside their personal limits, but need to make a decision whether or not to go. The instructor/divemaster will say "it's ok to go", they are not sure and make a decision based on their limited experience and the instructor talking the talk.

Most of the times this goes to plan without a hitch, but sometimes it doesn't, and the fact that it's tropical water with good visibility doesn't mean a lot if the doodoo hits the fan. Whether this is in a cavern, in a sea cave, on a tropical wreck, on a deepish dive, in a blue hole, too many examples of spots where fresh out of OW divers are asked to go and if something happens chances are they will not surface.

I don't really care about the narcosis vs tropical/cold water scenario. It's a given that tropical circumstances can lure you into deeper, more riskier dives, however this is foremost the case of more "experienced" divers (let's say 50-200 dives range), who dive locally in bad vis, and then go on a tropical scuba holiday. It's the ideal sweetspot of ego, overestimation... Not so with newly certified divers.

What I do have an issue with is the trust me aspect of the dive. Basically the OP can't make an informed decision based on his own experience. He can't weigh risk vs benefit, because he doesn't really know what the risks are. Instead he relies on the risk vs benefit decision of his instructor/divemaster, and that's never a clever idea, because he can't look into your head and will make his decision based on his experience (it's an easy wreck, done it thousands of times with students) in the worst case or make his decision based on his experience with you (I've trained them, they seem comfortable in the water, their ascends were ok, yes he can manage) which is slightly worse but still not good because he can't look into your head. He doesn't know if you are stressed about this, if you remember the emergency scenario's etc.

In the end it wasn't a problem for this dive, I hope you really enjoyed it. But I wouldn't make a habit of leaving a decision like this in the hands of others. Take ownership of your own dives, and make decisions based on your own training, experience. If you feel it's not adequate enough to make the decision bail out of the dive.

Not easy to do, and even with technical divers I see from time to time people still making these mistakes (normalisation of deviance).

Cheers and keep diving ;-)

 

[Kevrumbo]

Once again, thanks to everyone who has weighed in. I've gotten what I had hoped to get in posting this topic....a much more informed perspective on how to approach decisions like this going forward. I fully expected to get get flamed a bit given the topic, but even those who thought it was an incredibly poor decision were constructive and helpful with their comments. As we all know that can be a bit of a rarity in internet-forum-world, so it was a pleasant surprise. Grateful to have found this site....I've got lots of reading to do in advance of my trip next month.

For my inaugural post, thought I'd ask for some input on something that has been on my mind since getting my OW last year. We were in Roatan, and my girlfriend and I did our OW certification. We're both pretty athletic and picked it up quickly and were very comfortable throughout the whole thing, including 4 dives between 40-60 feet. (I had done several "discover scuba" type resort dives before as well). So as it happened, the dive to the wreck that I had read a ton about was the day after we finished our certification and it wouldn't happen again while we were on the island. The catch? It sits at 110 feet. We asked the dive shop if that was do-able, and they said yes.....we would just do it as one of our "adventure"/specialty dives and pay an extra fee. We went out the next morning, did the dive, and it was fantastic. There was minimal additional training aside from "stick with the group". We did, and everything was fine. The DM was attentive the whole time and the group was small. The DM also checked our air a couple of times along the way.

In the process of furthering my education I've spent some time reading many of your posts here and kept thinking to myself....wait a minute, diving to 110 feet on my first dive as a certified scuba diver??? That was a TERRIBLE idea.

So i guess my question is.....was this a situation that it was a bit of an overreach, or is this a "don't dive with that shop every again" type of thing? All in all I was very happy with the shop and their staff.

Some details for those not familiar with Roatan that may or may not affect the verdict:

-Water was 80+ degrees, zero current and perfect visibility
-The site was just off shore
-There is a decompression chamber nearby
-The wreck is at the bottom of a wall, so after you visit the wreck you slowly work up the wall towards the surface, so a slow ascent is built-in to some degree.

There was some talk for sure, including mention of narcosis signs and remedies. Also covered the plan and the time we'd be spending at the wreck before we had to begin ascending. But it was more of a briefing than instruction...nothing nearly as in depth as what Jim mentions. Luckily, neither of us noticed any signs of narcosis...perhaps b/c the deep part was at the beginning and we only spent about 10 minutes at the wreck?

Another detail that i neglected above....there were actually 2 DMs, one of which had a pony. (There were 6 divers so the entire party was 8)
I'd really appreciate any feedback here. Obviously in retrospect I would've made a different decision but that's part of why I'm asking this....to get some better perspective on when to "roll with it" and when to put the brakes on it.

Below is an example of the contingency planning for this dive that your Dive Guides and Instructor were aware of, but you as a Basic Open Water Diver do not yet have the formal training and instruction AND most of all -experience! -to undertake safely with confidence & competence. The point is, there are prudent reasons for holding the Basic Open Water Diver to a limit of 18meters/60feet Max depth while gaining the experience of logged dives and undergoing further advanced training. [Again, can you tell us what your SPG reading was when you started your ascent from 30 meters/100 feet average depth after ten minutes, and/or at least what was pressure reading, size tank cylinder used and total dive time when you surfaced??]

Looking at this objectively from the perspective of how much gas reserve needed for Air Sharing in an Emergency Out-of-Air Contingency for two divers at an average depth of 30 meters/100':

Given: For each teammate using an 11 liter/bar tank (AL80), and having a volume Surface Consumption Rate (SCR) of 22 liters/min -same as 0.78 cuft/min in US Imperial units (a reasonable breathing rate for beginning to novice divers)- using an example NDL air dive to 30m (4 ATA) average depth in Open Water.

Emergency Reserve/Rock Bottom calculation, from 30 meters to 15 meters at an ascent rate of 9 meters/ min and from 15 meters with one minute stops every 3 meters to the surface:

Depth (ATA) x SCR (Liters/min*ATA) x Time (minutes) = Liters
4.0 x 22 x 1 = 88
3.7 x 22 x 0.3 = 24
3.4 x 22 x 0.3 = 22
3.1 x 22 x 0.3 = 20
2.8 x 22 x 0.3 = 18
2.5 x 22 x 1 = 55
2.2 x 22 x 1 = 48
1.9 x 22 x 1 = 42
1.6 x 22 x 1 = 35
1.3 x 22 x 1 = 29
1.0 x 22 x 1 = 22

Sum Total Volume: 403 liters

Divide by the tank rating in use of 11 liters/bar (an AL80 cylinder) equals 36 bar --> round it up to 40 bar Emergency Minimum Gas Reserve/Rock Bottom absolute reading remaining on your SPG at 30 meters --this also happens to be the pressure in bar needed for one person in an emergency contingency to reach the surface with the above arbitrary conservative ascent profile.

So ideally for a two person buddy team, multiply 40 by 2 which is 80 bar needed for both to reach the surface (sharing Air in a buddy Out-ot-Gas contingency).

But realistically, for two novice divers stressed: 80 bar plus 30% of 80 bar equals 104 bar Rock Bottom SPG reading. (i.e. Equivalent to a stressed SCR of 1 cuft/min or 28 liters/min). A full AL80 cylinder is 207 bar, so in a nominal & normal dive, this Dive Team has a usable amount of roughly half tank each (100 bar) at 30 meters average, before encroaching on the Emergency Minimum Gas Reserve/"Rock Bottom" SPG reading of 104 bar. Ten minutes bottom time at an average depth of 30m would result in 80 to 90 bar of Air consumed for the Novice Diver (i.e. A Depth Consumption Rate at 30 meters of 8 bar/min), so this turned out to be a "do-able" dive profile within NDL and the above parameters. . .

 

[CuzzA]

Going forward I'll share a link with a calculator that makes it a little easier to wrap your head around what @Kevrumbo is talking about. DiveNerd - Rock Bottom Calculator, Imperial Units

The bottom line is you have to know what your rock bottom is for both you and your buddy and vice versa if one of you were to have a catastrophic loss of gas or a failure to deliver gas so you both can safely make it to the surface.