Diving recreational depths w/o computer...

[Tollie]

In my work with students and guests I use a bottom times and tables (PADI) with a watch as a backup. My dives are at known sites and run following established profiles. Tables more useful to me as they are consensual… I don’t have to worry about different guests with different computers. I think from a liability point of view and from a “conservative diving” perspective tables are the way to go. On some sites I’ll use the “wheel”… those that are really multilevel… say a deep wall descending from a shallower reef.

Now in my personal diving I use both tables and computer. On a liveabord, say, with multiple dives 3, 4 or 5 per day I rely on the computer. For heavy diving I’ll go EANx and of course conservative profiles that are shaped as Pug described… also longer and deeper stops.

 

[Robert Phillips]

I guess I should read the whole thread before posting, eh?:11:

 

[bradshsi]

Regardless, I am back to my original question - those of you who do use tables, why do *you* use them?

Vandit

For my diving I use the PADI RDP.

Curiously enough it raised a few eyebrows on the last dive boat I was on. People wanted to know what I was referring to pre dive since pretty much everyone else just geared up and jumped over the side.

I use them for two main reasons.

1. They are cheap. For the diving I do they meet the requirements and save me from having to spend $300 buying a dive computer. (the $300 figure is based on the features that I'd want if I ever bought one).

2. They help in the predive planning stage. I noticed with the computer the tendency is to jump in the water and plan later (although this is obviously a user fault and not a computer defect ). With the tables you pretty much have to refer to them and note down maximum depth and time. This is particularly the case for multi level dives.

 

[vkalia]

Bradhshi & Tollie - thanks... that was what I was trying to get at.

Yeah, I agree that tables are more conduicive to pre-dive planning. While the same sort of stuff can be done with computers, it is a bit more clunky and limited.

Cheers,
Vandit

 

[vkalia]

Of course the downside is that you also lose all of your arguments as well.

Ah, the curse of the pessimistic - I see it as the better man won!

 

[BKP]

I think the tables are viable for understanding what the computers are doing behind the scenes... and, we subscribe to Pug's theorem for most of our rec dives, anyway.
However, we *still* carry computers because I'm a type A that loves to analyze each dive (part of the fun), and the downloads are priceless. (Perhaps it's just me that enjoys the post-dive aspects of a computer as much as pre-dive).

 

[do it easy]

For the local quarry dives, I don't usually don't use a computer. The quarry has roughly three levels- 20', 50', and an 80' level. I base my dives on time in the 50' area and triple count time in the 80' depth and roll it into the 50' time. For example, 20 minutes at 50' and 10 min at 80' would be "equivalent" to 50 minutes at 50'. At the end of the dive, I'll spend time shallow, either hanging on the line or cruising around the 20' area.

I'm sometimes bad about surface intervals when I dive my doubles, so with repetative dives, I spend much more time shallow during the ascent and/or bring along a deco bottle.

I'll sometimes wear my computer as a backup if I know it's going to be a busy day.

Keep in mind that this is not something that I decided overnight. I have many dives in this quarry and I am continually tweaking my "deco theory."

 

[Dan Dan the Scuba Man]

I dive using both table and a computer on my consol...

I use the table because thats what i was taught to use and it more or less became secondnature to me to use them... my computer i use more to log my dives and for it to keep tabs on my depth and time down..

The only thing i could see wrong in tables is there's always the chance you could mess it up, if your doing deep depth frequently this could run you into some seriouse problems...

regardless i like both and i'm not about to change my ways of planning my dives.:doctor: :fro:

 

[AquaDuck]

Tollie scribbled:
In my work with students and guests I use a bottom times and tables (PADI) with a watch as a backup...Tables more useful to me as they are consensual… I don’t have to worry about different guests with different computers. I think from a liability point of view and from a “conservative diving” perspective tables are the way to go.

I agree with you Tollie, we have found that keeping our students' exercises going by having them work out their predive plans and post dive pressure groups using the tables make things easier to verify that everyone is jumping the hoops right. We spend some time on the OW and again on AOW discussing the concept behind the RDP and emphasize the need for managing bottom, safeT stop and SIT times.

We do however recommend that our students also purchase dive computers *if* they can afford it but to never abandon their drilled in habits of predive planning and post dive debriefing and analysis. We have found that inevitably our students that most often than not become regular certified divers with us on our trips, use the computers during the dives and the tables as backup pre and post dive for making sure that everything's going to plan. It also helps when we start teaching EANx courses coz by then table use is nothing new to most of them anymore. It also gives them the confidence to speak up when they go on holiday and the predive planning stretches them outside their limits - we've seen people simply shut up and go with the flow, after all the DM should somehow read their minds to know what bottom time restrictions they have

 

[Web Monkey]

A table and a computer are both "black box" devices which give you a readout without telling you anything about the details of what is going on inside. One requires a bit more manual work. Arguing that using a table or a computer affcts your knowledge of what is going makes no logical sense whatsoever - what, the computer uses the Force and switches off my brain?

The really funny part is that both the dive information you get from a dive computer and the dive information you get from a table are actually derived by applying the current conditions as input to a known formula, and calculating the dive times and surface interval.

They both do do the exact same thing, however the tables do it based on a square dive profile, while the computer does it using the actual dive profile.

People who don't like computers shouldn't use tables either, since they do the same thing in the same way, except the table starts out with an assumption instead of real data.


Terry