When is it okay to abandon your dive buddy?

[Centrals]

Who uses tables for diving? Show me where people write down the dive plan for every dive.

Virtually everyone uses a dive computer nowadays. These have different algorithms which all result in different NDLs for the same dive: Buhllman + GF (which GFs?); RGBM (which 'P' setting); Other proprietary Suunto algorithms ('P'?); DSAT; et cetera.

All fine if you're doing shallow dives, but as soon as you get to around 30m/100' and especially on air you can easily exceed the NDL with a single tank. Now add in differences between diver depths, even a metre makes a difference to the NDLs

Confusing indeed.

25 yrs ago!
I believe most OW classes are taught using computer(could be wrong) nowadays. And I hope the instructor will point out to the student that various algorithms are being used in dive computer( even from the same manufacturer eg Oceanic) and the resulting NDL is completely different
I dive with two different brands of computer with different algorithms and the difference can be quite substantial.

Confusing indeed.

 

[Wibble]

BTW no problems in using (as an example) the PADI RDP tables to illustrate the principles of deeper = less time, mandatory safety stops, etc.

 

[Taliena]

The easiest way to programm a computer is to lock if a diver don't do what the computer wants to do. The programming skills need to be way much better if you want to recalculate missed stops.
So the cheapest way to produce algoritms is to skip the options that a diver doesn't do what a computer expects.
The new suuntos have a complete different algorithm (novo). They are way less conservative than the older ones. But yes, they still lock. And another problem with the D5 for example: you cannot add an extra decogas if you didn't put it in and on before the dive.

 

[Centrals]

All bet is off if the diver is not checking his/her dive computer or understand why certain number in one certain sector is decreasing as dive time progress.
Do not blame the computer the culprit is the end user.

 

[Wibble]

The easiest way to programm a computer is to lock if a diver don't do what the computer wants to do. The programming skills need to be way much better if you want to recalculate missed stops.
So the cheapest way to produce algoritms is to skip the options that a diver doesn't do what a computer expects.
The new suuntos have a complete different algorithm (novo). They are way less conservative than the older ones. But yes, they still lock. And another problem with the D5 for example: you cannot add an extra decogas if you didn't put it in and on before the dive.

Alas it's so easy to do some dumb-ass programming choice which massively inconveniences the end user. Such as locking the damn thing up when switching from freediving mode into a dive mode.

Demonstrates sloppy arbitrary programming practices. If you're one minute over or switching between modes, then you could just penalise the next dive a little on surface interval, or have a threshold.

The nonsense is that schools constantly loan out computers; what about sharing one between a couple of people?

All bet is off if the diver is not checking his/her dive computer or understand why certain number in one certain sector is decreasing as dive time progress.
Do not blame the computer the culprit is the end user.

I'm happy to blame the computer when they have lousy and confusing user interfaces. Some computers have excellent interfaces and are a joy to use. Others are just plain nasty.

If something's confusing, hard to interpret and difficult to find the information, then it's the design that's at fault.


There's only two industries that refer to their customers as "Users".

The IT industry and drugs pushers.

 

[Aura]

I believe most OW classes are taught using computer(could be wrong) nowadays.

When I was OW certified in 2016, and AOW certified this year, there was no mention of computers, tables, or any sort of decompression theory whatsoever. If going exclusively by what instructors have taught me, the only limiting factor to my bottom time is air. Everything else I've learned on my own.

EDIT: As for the actual topic, I think it's very important that you have a talk about what you expect of each other as buddies, and go through some of all those what-ifs (in this case, getting separated from the group).

 

[Taliena]

In 2010 tables where taught. I have done 4 dives over 100m in 2011 and 2012 without computer. Just runtimetables.

You can say it is a user error if a computer locks, but sometimes you plan a dive without decogas, but take it with you because you don't know what to expect under water. Then you take it and switch it on you computer. That is not possible on a suunto D5, if you did not enter a decogas before the dive, forget it during the dive. This will result in an '505' modus. So not my favorite way of programming.
On Shearwater or Heinrich Weihkamp you can always switch on and off gases, or change gases.

Okay, I talk about a little bit more experienced using, on a single tank dive I never had the new D5 in error. But the beeps are sometimes annoying and not stoppable.

 

[Centrals]

When I was OW certified in 2016, and AOW certified this year, there was no mention of computers, tables, or any sort of decompression theory whatsoever. If going exclusively by what instructors have taught me, the only limiting factor to my bottom time is air. Everything else I've learned on my own.

EDIT: As for the actual topic, I think it's very important that you have a talk about what you expect of each other as buddies, and go through some of all those what-ifs (in this case, getting separated from the group).

Which agency did not teach either computer or table 5 yrs ago. How did you plan your dive after finishing both OW and AOW?
I dived a lot around SE Asia and met plenty of divers from all over the world. Literally diving with an insta-buddy all the times and I have to be very careful how to deal with them. Some of them believing they are the best and most knowledgeable diver in the world.

 

[Aura]

Which agency did not teach either computer or table 5 yrs ago. How did you plan your dive after finishing both OW and AOW?

Both my courses were PADI. When I was only OW certified, I didn't have a sufficient understanding of deco limits, but none of my dives were long or deep enough for it to be relevant (I'm saying this in retrospect, at the time I just didn't know). I've since bought a computer and learned how to use it.

Some of them believing they are the best and most knowledgeable diver in the world.

I think this is a dangerous attitude, regardless of a diver's training and experience.

 

[Wibble]

As for the actual topic, I think it's very important that you have a talk about what you expect of each other as buddies, and go through some of all those what-ifs (in this case, getting separated from the group).

That’s a very good point but difficult to do in a general sense — to explain to students the limitations of the buddy system and why you should aim to be self sufficient.