Doing 'Light Deco' as a recreational diver

[String]

I incur them fairly often. I dont see any reason for an NDL to cut short an enjoyable dive.

 

[jeckyll]

I'll just run down and answer some folks in line:

onfloat: I wouldn't call you slow, just didn't want you to tune out at the talk of a computer

MikeFerrara: I'm not advocating what people do, I was curious if alot of folks around here dove that way. Personally, I'm not a great fan of the 'no fall back, if everything works 100 % it'll be allright" strategy. If you see my post, my buddy and I did more planning for this dive than anyone else (from what I could tell), we knew we wouldn't exceed rock bottom for this dive and we had extra gas in case of an emergency. I have no plans for following the idiots

ianr33: my buddy's been diving (including deco) since long before nitrox was available. Now that we are diving together a lot he's going to take nitrox, but didn't get that done before the trip

roakey: I agree with your assessment and that's the part that I was wondering about. I guess I just have a different approach and what I saw on the boat wasn't what I would consider 'good practices'. Note, this is not the fault of the crew IMO, they provided all the necessary information.

do it easy: I keep my computer around for interest sake I plan my dives up front and know what I'm going to do before hitting the water. I haven't switched it to gauge mode yet

String: Do you plan on exceeding the NDL's or is it just one of those "I'm here and not ready to leave" things? If so, do you carry extra gas and do you have a contingency plan for missing any stops or having the computer crap out on you on the way up? Just curious

Thanks for all the responses.

Bjorn

 

[String]

on exceeding the NDL's or is it just one of those "I'm here and not ready to leave" things? If so, do you carry extra gas and do you have a contingency plan for missing any stops or having the computer crap out on you on the way up? Just curious

Thanks for all the responses.

Bjorn

A bit of both. If its a dive where we MIGHT go slightly beyond NDL then sometimes we do. I always carry redundant gas, always carry back up tables and always aware of how long my gas is going to last me at depth/stop depths even on normal dives. I also dont do silly amounts of deco with that method - 5 mins or so is usually it.

Im also aware from tables just how much i'll get for square profile of my depth if the computer craps out.

If im doing a dive i KNOW i'll run into deco its done with v-planner, timer and full hog.

People are far too scared of relatively minor deco forced in part by some agencies just black and white "NDL is ok, anything over isnt". Ive seen a LOT more dangerous profiles of people riding their NDL than people who didnt do that but did a few minutes of stops instead.

The 2nd level course here teaches and allows mandatory deco and its accepted as such that its better to hang around a few minutes having gone a bit over than it is to go to within 1 minute and just do a safety stop.

 

[Meng_Tze]

If im doing a dive i KNOW i'll run into deco its done with v-planner, timer and full hog.

Any particular reason for full hog when running deco dive? (just asking)

 

[String]

Deeper, deco will be far longer needing more gas. It'll be accelerated deco so requiring different gases and the contingency associated with that. Far more scope for error and far more serious consequences if it all goes wrong.

 

[jpcpat]

Lots of divers ride their computers up. I've even done it a time or two. 1 minute of ndl time vs 1 min into deco is not all that significant. You don't automatically die when your comp shows 0 time left.

That said, I'm not comfortable pushing limits. All tables, computer or otherwise, are just theories, albiet with lots of empirical backup. There's no guarantee. The deeper you get into the warning zone, the faster the risks are piling up. Most divers think it's safe as long as they have time on the comp. I disagree.

 

[matt_unique]

I bet this happens a lot. Most people don't realize recreational computers, even those that provide basic deco information, are not at all suitable for deco diving. It would be an eye opener to take a "deco profile" from a recreational computer and compare it to best accepted models/software such as V-Planner.

--Matt

 

[ArcticDiver]

I bet this happens a lot. Most people don't realize recreational computers, even those that provide basic deco information, are not at all suitable for deco diving. It would be an eye opener to take a "deco profile" from a recreational computer and compare it to best accepted models/software such as V-Planner.

--Matt

What makes one algorithm "better" than another?

As differentiated from merely making a dive longer or shorter; what makes one algorithm "more conservative" than another?

Is V-Planner more "accepted" than, say DecoPlanner or its' like?

Are any of the algorithms, however implemented in paper tables, topside computers, or take along computers any "safer" than another?

 

[roakey]

1 minute of ndl time vs 1 min into deco is not all that significant. You don't automatically die when your comp shows 0 time left.

You are absolutely correct, it's not that significant, which isn't the point. Depending on the dive, even if you're one minute away from deco you probably don't have enough gas to get you and a buddy to the surface with normal safety stops. This becomes even worse if you have mandatory deco.

Run your numbers through some rock bottom calculations (do a search on the board, you'll find it) and you'll probably discover that you're in deep do-do one minute away from deco, gas wise.

So the not so subtle difference is that when you say "not all that significant" you're implying "it's almost as safe" but when I say "not all that significant" I'm implying "just as dangerous".

Roak

 

[String]

What makes one algorithm "better" than another?

As differentiated from merely making a dive longer or shorter; what makes one algorithm "more conservative" than another?

Is V-Planner more "accepted" than, say DecoPlanner or its' like?

Are any of the algorithms, however implemented in paper tables, topside computers, or take along computers any "safer" than another?

Some models are older and more up to date than others. Decompression theory is still a lot of guesswork but it IS advancing.

Example being original navy tables vs newer navy tables with doppler factored in and so on.

The main ones these days are gradient factors on buhlmann (a crutch basically to allow Buhlmann to give deep stops) and VPM (B/BE currently as 'A' wasnt great).
Both these branches are more in thinking than the older style bend and mend that bring a diver shallow quickly then keep him there for ages (and totally ignore microbubble formation etc).

So yes, in my view some models are "better" than others. More specifically newer thinking i feel is safer than 20-30 year old models based on bending goats with no human input to adjust the theory.