Trusting a computer

[Lorenzoid]

. . .
The charter I went on, they told us the first dive depth literally 20 minutes before we anchored and then the second depth on the way to the second stop. So it's impossible to plan your 2 or 3 tank dive ahead of time. I did calculate everything on my computer, but I guess I'm curious if my computer is right.

I'm impressed they even were able to tell you a depth with much clarity. Except on wreck trips, square profiles are rare. Often, it's more like "The bottom slopes down to X feet in the beginning, but we will try to stay around Y feet, and then after we make our way to the ________ we will be around Z feet .... You can either follow me or do your own thing, but everyone has to be back on the boat no later than M minutes after entry."

As I think others have said, your computer is "right" in the sense that people who have dived within the limits dictated by that computer haven't gotten bent any more than people who have dived within the limits dictated by any other computer or tables. It's been validated by enough actual diving to give people confidence in its safety.

 

[Freewillow]

On my first trip to Coz. I rented all the equipment. The dive OP didn't require a computer. The DM's instructed anyone without to go no deeper than they do. .

Please make sure that you do not go to that op again. . Cozumel is known for possible strong currents, including possible washing machines...................

To not require a computor and to tell customers to remain shallower that the dive master is down right criminal..........................except if the dives were made with a bottom @ 45 feet .

 

[JohnnyC]

I don't have a suunto, I've cressi leonardo that runs another variant of the dreaded proprietory "RGBM". As a side note, the leonrado doesn't seem to mind reverse or sawtooth profiles so much, as long as you don't trigger its "rapid ascent" logic. If your "ups" are too far too fast it may penalize you on the next dive. The more time you spend above ~7m at the end of the dive, the happier it is.

The joys of proprietary algorithm implementations! People think "RGBM" in terms of a single algorithm when, in reality, almost all iterations of it are different in their implementation.

"Why does it behave like this?" "Can't tell you, it's proprietary....."

 

[Freewillow]

I got rid of my Cressi Leonardo. Once you passed the NDL it really behaved funny. Did add some deco time while you were going up. For them you have to go to your deco depth as soon as possible. I hate this. A nice and cheap computor for beginners though.

 

[MB NZ]

The joys of proprietary algorithm implementations! People think "RGBM" in terms of a single algorithm when, in reality, almost all iterations of it are different in their implementation.

That is correct, there are variations of algorithm interpretation even within the same brand of computer.

Suunto RGBM Dive Algorithms

 

[scubadada]

A very conservative decompression algorithm is also very safe. The less time you spend underwater, the less the risk. Of course, you may want to spend more time underwater for the cost. I don't think any of the commercially available decompression algorithms have been shown safer or riskier than any other, I think they are all very safe. I will continue to dive DSAT, as I have for the last 14 years, 1150 dives.

 

[Coztick]

Please make sure that you do not go to that op again. . Cozumel is known for possible strong currents, including possible washing machines...................

To not require a computor and to tell customers to remain shallower that the dive master is down right criminal..........................except if the dives were made with a bottom @ 45 feet .

Thank you for your concern.
It was only after the first visit and some self-education that I realised I needed to take responsibility for my own safety.
My wife and I will continue using the same AI as she doesn't dive and feels very comfortable and safe while I am out diving. As for the dive OP, after 55+ dives with them, I know what to expect. A ride out and back is all I'm asking for.
To expect more is foolish.

 

[Freewillow]

@wetwelder, we are in agreement . Just one question AI, refers to what? Thanks

 

[Fedaykin]

Do I trust to technology, yes…

Do I rely on DC rather than my instinct, no…

Problem here is lots of divers who started without tables just do whatever computer says without understanding anything. If everything is ok then there is no problem. But if there is a problem with their equipment they become like a fish out of water.

Also I don’t understand how can a groups gets separated down the water. If your dive 6 people together you get out of the water 6 people together. When someone is at his/her turning point then every one does. That’s why I prefer to dive with the same persons at all of my dives.

If my computers doesn’t seem to work properly (never happened) I have to understand something is not right. This is same for depth and air consumption. If you leave your brain to a dive computer this kind of instincts doesn’t get better. After some time you have to look to your gauge just to be sure at which depth with how much air you have left. If any data doesn’t seem to be right check it with your buddy and dive leader. If you know and trust them then there is no problem. If you are new with those persons, as an AOW or CMAS 2 Star etc. you are responsible from your own and you don’t have to follow every order blindly. If it seems that something is wrong than finish the dive and start ascending procedures. They have to follow you. If they don’t, ascend at your own and never dive with them ever.

 

[Freewillow]

@Fedaykin: what do you mean by DC?

One should never get separated from his/her body. But to be separated from a group can happen, especially if you have current and/or low visibility. Not a big deal if you are an experienced diver, but it has happened to me .