Total Newbie

[KatieMac]

Hi everyone,

I'm new here and new to diving. I just got my Open Water certification because I was tired of being on the surface while my family was down under.

I'm looking forward to learning from all the seasoned divers here.

First order of business is a dive computer. I have been cautioned by some to stay away from dive computers that are too conservative (Suunto, Mares, Cressi) and go with something that is more liberal. I'd like to get everyone's thoughts.

 

[decompression]

Congrats Katie! If I may comment about Suunto's. I'm really not sure why everyone is so against conservatism. Especially at the open water level, in cold water and if you are not a 20 yr old Navy Seal. There are a lot of computers and a lot of algorithms but genuinely they are more of a "discussion topic" than a severe handicap to actual diving. Go with any computer that will get you into the water and develop your skills and have fun.

 

[tbone1004]

it's not that they are too conservative or more liberal, it's one that you get to choose how conservative the computer is based on conditions. I am much more apt to dive a liberal algorithm when I am in warm water doing a drift dive, than I am where I will be doing a working dive in cold water.

Gradient Factors | Dive Rite
That is a great article on the hows and why's. While not cheap, the best computer on the market is the Shearwater Perdix, and you'll be supporting a local Canadian country. Well local in the most liberal sense since they're on the west coast, but still Canadian.
Oceanic Dual Algorithm | Simply Scuba Blog
This is a discussion on the Oceanic dual algorithm that they use

Not sure where in Ottawa you are, but Dan's Dive Shop is a fantastic shop in St. Catherines.
http://dansdiveshop.ca/

 

[KatieMac]

Thank you both for your responses.

In my mind (and as a diver who has done 4 dives I could be totally wrong), since I am pretty small - about 2/3 the size of my husband and brothers-in-law would this not play a role in residual nitrogen / safety stop times?

 

[tbone1004]

not necessarily as it is about pressure gradients across the tissues. Decompression theory is still very much theory and it is all about experimenting with what makes you feel ok at the end of the dive. If you are interested in it, I would suggest reading through the articles on DAN and also through the papers that are published by the Rubicon foundation. It is enough to make your brain spin, but it goes very in depth

 

[KatieMac]

not necessarily as it is about pressure gradients across the tissues. Decompression theory is still very much theory and it is all about experimenting with what makes you feel ok at the end of the dive. If you are interested in it, I would suggest reading through the articles on DAN and also through the papers that are published by the Rubicon foundation. It is enough to make your brain spin, but it goes very in depth

I'm a data junkie and researcher by profession so it sounds like fun.

On that note, I would love to get my hands on tons of dive log data - different people, different locations, etc. Is there a specific board here that would be best to see if people know where I can get something like this?

 

[tbone1004]

rubicon will have most of the information that you are looking for. the volatility of body composition and theoretical nature of decompression theory does not allow for anything real to be learned by dive profiles of varying divers. All you can do is go on the dive and say whether or not you feel good. This is how the original navy tables were made, it was all trial and error and lots of fit males in their late teens and early 20's were bent. Unfortunately because temperature, hydration, properly fitting gear, etc etc all adjusts how your body both ongasses, and offgasses, it is essentially impossible for any empirical data to be learned by studying dive profiles.

The buhlmann ZHL-16c with gradient factors takes a theoretical tissue loading of 16 different compartments in your body and you get to choose the theoretical loading percentage that your body experiences when you surface.

 

[USdiver1]

Just as a point of continuing education, my recommendation would be to dive recreational tables for a couple of years prior to purchasing a computer. There are tables available for air, 32% and 36% oxygen, etc. Use of the tables will not only assist you in learning the repetitive dive groupings, but allow you to calculate and plan your dive beforehand, rather than blindly following what pops up on your computer screen. I'd spend my money on a good regulator, wet suit and/or buoyancy control devise, prior to a computer.

 

[DiverDownD3]

At the beginning you will likely run out of air before you hit your NDL. At least that has been my experience on most dives.

 

[KatieMac]

At the beginning you will likely run out of air before you hit your NDL. At least that has been my experience on most dives.

Actually, I'm really good on air. I did a 63 min dive and came up with 1100psi and another 60 min dive and came up with 1000 psi. Each time, I had more air than seasoned divers on the same dive. It may be because I'm about 2/3 the size of these big guys.

Having said that, I've only done 4 dives so this is not a strong indication of the future.