Affordable Dive Computers

[Brett Hatch]

Agree with @wetb4igetinthewater that tables are talked about a lot more than they are actually used.

The thing to think about with tables as a backup, is that in order for that strategy to work, you must do the calculations before and after every single dive. Otherwise, when your computer fails and you go to look up your dive times, you will not have enough information to do so. Also, for several multi-level dives in a sequence, the tables are going to be dramatically more conservative than they need to be.

If you are considering using tables as a backup, ask yourself if you are truly going to put in the effort, and be bound by shorter dives and longer surface intervals. I think anybody who sits down and thinks this through will realize that a backup computer is a better solution.

All that being said, I still would advocate for coughing up for a good computer instead of two cheapo ones. And if you want a backup, buy a good computer as a backup. Deep6 Excursion and Shearwater Peregrine are solid choices for this. Incidentally, I don't recommend using a piece of crap reg as your backup, for the same exact reason: in the situation where you actually need it, you do not want it to be a piece of crap.

Edit to add, all this is especially true if the only diving you do is on expensive vacations. For day-trip local divers, the worst case scenario of pinching pennies here is not that bad. The worst-case scenario on a liveaboard trip is huge. Those things are like $500 a day, so in the big picture, are you really going to miss the $500 you spend on decent equipment?

 

[Belzelbub]

Now I don't have any data to back this up, but my gut feeling is that the people who like to use tables and have that as a backup plan to their dive computers is a marginal percentage of the divers out there. So small, it almost isn't worth talking about as a practical option.

I’d agree.

I’d also like to hear from that minority who have actually had to, and how it worked out for them. I’ve dove tables before, and still have a few around. Theoretically, I could plan a second dive with tables, but I know that it would be cut way short. I could estimate max depth and dive time reasonably enough, but I wouldn’t be able to estimate average depth. Even on sites without big depth changes, there is enough structure that I’m well off the bottom for the majority of the dive.

 

[wetb4igetinthewater]

I’d agree.

I’d also like to hear from that minority who have actually had to, and how it worked out for them. I’ve dove tables before, and still have a few around. Theoretically, I could plan a second dive with tables, but I know that it would be cut way short. I could estimate max depth and dive time reasonably enough, but I wouldn’t be able to estimate average depth. Even on sites without big depth changes, there is enough structure that I’m well off the bottom for the majority of the dive.

That reminds me. I need to replace the dive tables in my dive planning doc with using multideco. That's actually a big shortcoming of this document:

 

[FishWatcher747]

OP, are you aware you can buy a perfectly good and barely used dive computer with all the appropriate information you need for recreational diving on ebay for about $175.

I know I have done it twice.

If anyone is on a dive boat I am on and they don't have their computer or it is not functioning I can lend them one and I still have the 2 I dive with, one on console, one on wrist.

 

[tursiops]

I never understood the need for multiple open water training dives for my Nitrox certification back in 1995. If memory serves it was 2 dives. Still seems like a huge bunch of silly to me.

That's why it was ended many years ago.

 

[scubadada]

That's why it was ended many years ago.

Do you know when the dives ended, they were still in place in 2002?

 

[tursiops]

Do you know when the dives ended, they were still in place in 2002?

2006

Info - History of PADI's Enriched Air Nitrox course

I was looking for something else in the old PADI Training Bulletins and found this information: 1996 EANx first offered. Prerequisites were AOW or OW plus 10 logged dives. 2 OW dives were required. 2000 Prerequisites of AOW/10 dives dropped. 2004 DISCOVER EANx offered; 32% maximum, no...

scubaboard.com

 

[Centrals]

Preferably I would like two computers that I can easily replace the batteries quickly if it dies between dives and are on the same dive algorithms.

User change of battery is the requirement.
Oceanic Veo 4 + Aqualung(from i100 - i330).
Oceanic runs on DSAT or PZ+ while Aqualung is on PZ+.
DSAT is a far more liberal algorithm than PZ+, so please use the Aqualung as the main computer if you set the Oceanic on DSAT.

Dive Computer Algorithms For Dummies

Let’s look at the theoretical models behind modern dive computer algorithms, the differences between the various options and the ways you can influence the algorithm.

dipndive.com

The option is huge.
Just shop sensibly and have fun in your adventure.

 

[Chavodel8en]

Since folks asked about experience diving tables: When I was alot poorer, when my computer died, for several years, I relied only on tables + depth gauge and cheap watch. But I was just doing shallow local shore dives. It did limit my diving. I avoided deeper sites: No North Monastery dives or the deeper parts of Pt Lobos, as those would be difficult to dive on tables.

When I had a trip to Oahu planned, I bought a computer. I would not want to try to dive the wrecks and other sites on tables - dont know if it is even possible.

However, another question posed was: do you rely on tables for backup? My answer: Now, not really, even though I only have one computer. I dont even know where that old depth gauge is or if it still works, and the $30 Ironman watch I used has long since died. But I dont really do liveaboards or week long diving vacations. I dive locally and do a couple dives here and there on vacation. If my computer dies, my diving that day will probably be over and I'll have to rent a computer.

Although now that Im a little more settled I think my next purchase will be an air-integrated wrist computer and my Deep 6/SPG can be my backup. Rather than getting a cheap back up computer.

 

[Seaweed Doc]

Thoughts for the OP:
Computers can fail, so I understand your desire for a backup. I've had computers fail twice on me while in water. One was user error: I forgot to replace the battery knowing it was running low after the prior dive. The other was not: The electronics compartment (not the battery compartment) somehow flooded mid-dive. Computer was D-E-A-D dead.

I use one routinely, because I can afford to do it and don't want to sit out or revert to tables either when teaching or on vacation. One is high end, suitable for tec diving. The other is entry level, not for tec.

Given your situation (no interest in tec) I'd suggest going with two identical models. You learn how to use one computer really well rather than sort of know how to use 2. I've found that with two different computers, I really lean on one or the other and get rusty on the backup.

Beyond that, it's up to you. On the low end, I love the readability of the Aqualung i330R. Bright colors, easy on old eyes, and low cost. But I don't like how the control buttons work. "Press both buttons at once for 3.2 seconds" is not a protocol I'm good at. (OK, it's not that bad but I'd rather press one button at a time and not have a differential response based on how long I hold it down.)