30m - deep?

[Ferg3333]

I consider a dive to be deep when I am no longer in my comfort zone and therefore it will hold a greater sense of the unknown. But as with any dive you cannot eliminate risk you can only look at ways of controlling and reducing the risk through redundancy of primary systems.

[nigelH]

Using words like 'deep' for it's emotive effect isn't really helpful.
Each dive needs its own assessment, I hate the jargon phrase 'risk assessment' as it implies too many bits of paper but that's the sort of idea.

I tend to plug in the kit for the dive based on my assesment of how long I'm going to be there, how long I'm going to take to get back and what might break during that time.

10 meters could be suicide on my oxygen rebreather, 60 meters on nitrox but just 1 meter on 10/60 trimix. Too fast an ascent with a deco loading could be very bad or too slow an ascent when freediving.

[Clare Gledhill]

I've always seen depth is pretty irrelevant once you have factored for gas. Time to the surface is what makes a dive serious to me - whether that is deco or exit time. Is 3000 feet back in a 6 metre cave deep or shallow? Well when you have a 60 minute swim to air it's a serious dive to me.

A very, very experienced technical instructor died in Ginnie Springs a couple of weeks ago. The entire system is 30 metres or less. He had drained both his on board RB tanks, both his bailout tanks and his body was found only a few feet from one of his full stages. In an environment where most of us can do not much more than a minute without gas, anything more than that is too far if we have none.

[PeeBee]

For me "deep" is when bottom time is so short it's not worth going there, I'm not (yet) deco qualified so whilst I would not have any problem diving to 40m and have in the past, I don't see the point if I can't stay a while to enjoy it. I love diving but don't want to spend the majority of the dive mid water, particularly in the UK, it could be slightly different if I was diving the Brothers and dropped to 40 then came up the wall slowly as we drifted.

My 2p

[Mark Chase]

Originally Posted by Clare Gledhill

I've always seen depth is pretty irrelevant once you have factored for gas. Time to the surface is what makes a dive serious to me - whether that is deco or exit time. Is 3000 feet back in a 6 metre cave deep or shallow? Well when you have a 60 minute swim to air it's a serious dive to me.

A very, very experienced technical instructor died in Ginnie Springs a couple of weeks ago. The entire system is 30 meters or less. He had drained both his on board RB tanks, both his bailout tanks and his body was found only a few feet from one of his full stages. In an environment where most of us can do not much more than a minute without gas, anything more than that is too far if we have none.

Yes, but logically that diver was 3000ft deep. Cave diving is on a par with deco diving as a base line.

15mins deco = 15mins into the cave

However you can blow off 15mins of deco you cant blow of 15mins into a cave. So we have to look at a OW dive which if blown off will likely kill you.

Maybe 90mins of deco? (total guess)

So a 15min entry into a cave is a bit like a deco dive with 90mins deco in terms of risk of death.

Mexico 14m deep 60mins into the cave is a bloody big dive for me and I am a LOT more nervous about doing it than I am about doing a 60m two hour dive dive in OW in the UK.

ATB

Mark

[MarkP]

Originally Posted by Mark Chase

So what do you consider a shallow dive?

If I can't bail out by standing up it's deep. More seriously, if I'm not confident I can solo it to the surface OOG it's deep.

Originally Posted by Mark Chase

There is no point telling us off for this, its just the comfort zone we have built up over the years. Its not big or clever its just the way things go. With experience at any depth you will soon find the "comfort zone" is 10 or so M less than the depth at which you regularly dive.

I've not told anybody off. I've simply implied that comfort zones can be misleading. Most people are comfortable when driving within a mile of their home, exactly where most accidents happen.

Originally Posted by nigelH

Using words like 'deep' for it's emotive effect isn't really helpful.

I disagree. It can be useful if it prompts a debate, which was the sole reason for my post.

Originally Posted by nigelH

Each dive needs its own assessment,

Which must include the understanding that it's possible to die in a 1m water.

(And I know about the journey to the site etc.)

I'm not risk averse. I seek it, as I expect many here do. I just thought a reminder of the inate hostility our chosen environment was prudent.

Diving is potentially dangerous. We shouldn't forget it.

[liamm]

Originally Posted by MarkP

I've not told anybody off. I've simply implied that comfort zones can be misleading. Most people are comfortable when driving within a mile of their home, exactly where most accidents happen.

As much as comfort zones can be misleading, being over cautions or misseadind risk can be misleading.

I dont think depth is the issue at all, if the dive is planned for and the gas is apprpriate with enough bailout or redundancy.

In some ways i feel that a 40m dive taken seriously is much safer than a 15m bimble done casually. I see loads of these types of dives - no redundancy (buddy / team or otherwise) and no thought to time planing. You can do a bouyant ascent much easier from 15m but i dont think that makes it safer.

i'd rather plan not to run out of gas, or as in Si's post yesterday have a team nearby to donate gas in case of equipement failure.

[GLOC]

As the person in that thread which mentioned 30m, to me it boils down to comfort zones, as has been alluded to already.

30m with 2 attentive buddies, lots of gas (2 twins of 32 and 4 stages of 50%) and a straight line to the surface didn't worry me; 15m solo would make me more concerned.

Good starting post Mark and it has promoted some debate, which is always good.

[wilbo]

Originally Posted by GLOC

As the person in that thread which mentioned 30m, to me it boils down to comfort zones, as has been alluded to already.

30m with 2 attentive buddies, lots of gas (2 twins of 32 and 4 stages of 21%) and a straight line to the surface didn't worry me; 15m solo would make me more concerned.

Good starting post Mark and it has promoted some debate, which is always good.

[scuba g]

Originally Posted by Buoyant Babe

This is what 30m looks like. That's me at the bottom. I think it's deep.

Attachment 5310

Is that your garden shed behind you?....Nice...I only got a shitty B&Q one!