Do I really need a computer?

[wedivebc]

I once did a dive trip in Thailand where the operator policy required a computer. Mine died first day so I used a bottom timer that I had also brought. After every dive the DM wanted to see everyone's computer. I just showed my BT and a he never said anything about it. All our dive profiles were within PADI air tables anyway so it seemed pointless.

 

[Joneill]

It has been a long time since my last dive, and I did just fine using the PADI charts to plan my dives. For my upcoming trip to Cozumel, I'll be with diving with a shop affiliated with a dive resort. All the dives are pretty scripted, so technically I won't be "planning" anything. I'll be doing two dives each morning, and I may be doing a night dive. Do I really need a computer in those circumstances? Do people even go diving these days without one?

While I imagine that very experienced divers can get by without a computer, I'm still not sure why anyone (esp. rec divers) would want to in 2017 given how cheap and useful they are? As you indicate it has been a long time since your last dive, I'd say it makes sense to get one so you can better track your critical dive info in real time - buying may be better than renting so you can get to know the computer's functions better - but it really depends on how often you plan to dive?

 

[Chavodel8en]

I dove for many years w/o a compu -- but I was only doing local shore dives that for the most part were less than 60'. I had no reason to have a compu, so I didn't.

However, once I had a vacation planned, I bought a cheap compu in anticipation, bc I wanted to do some deeper (80'-100') wreck dives where I wanted more bottom time.

If you are only planning shallow dives on your vacation, and not more than 3 (2 morning, 1 night) a day, then you can get by relying on tables and it may not limit your bottom time much -- as long as you have reasonable surface intervals. (unless you "dive the DM's compu," which you shouldn't do)

Personally, vacation dives are precious to me and I want to get every last minute of bottom time. I figure, I spend a lot of $$ to get these vacation dives, might as well spend an extra $200 and get a compu.

 

[BoltSnap]

There is plenty of diving in Cozumel that is deep enough that diving with a computer will very likely net you much more allowed bottom time than if you plan everything using tables.

Planning with tables is done using your maximum depth from each dive. So, planning with tables doesn't give you any off-gassing (or less on-gassing) credit for a dive where you (just for example) hit 90' for a minute, but then spent a lot of your time between 70 and 80 feet.

A computer counts your actual time at each depth that you're at. So, in the above example, a computer would let you stay down a fair bit longer on that dive. Or, you could stay down the same amount of time, but the computer would let you stay down longer on the next dive after your surface interval.

What he said above in addition to other benefits the dive computer gives you the tables don't: 1. automatic on (no forgetting to set the stopwatch), accuracy in time & depth, deco calculations (try to plan a dive with tables on a rocking and rolling dive boat and trying to follow the lines on the tables), logbook, dive statistics, multi-level diving, etc.

If you are going to use the dive tables, you would need a dive watch to keep track of your time underwater. Most "proper" dive watches will cost you more than what an entry level dive computer would cost you so there is no cost benefits at all.

Exception: If you are going to be cleaning boat bottoms in no deeper than 5 feet, there is probably no case for dive computers in this scenario.

 

[dmaziuk]

It has been a long time since my last dive, and I did just fine using the PADI charts to plan my dives. For my upcoming trip to Cozumel, I'll be with diving with a shop affiliated with a dive resort. All the dives are pretty scripted, so technically I won't be "planning" anything. I'll be doing two dives each morning, and I may be doing a night dive. Do I really need a computer in those circumstances? Do people even go diving these days without one?

Do you intend to dive ever again after that trip? If not, then it's a waste money, rent one from the shop if they insist.

 

[Kevo88]

What he said above in addition to other benefits the dive computer gives you the tables don't: 1. automatic on (no forgetting to set the stopwatch), accuracy in time & depth, deco calculations (try to plan a dive with tables on a rock and rolling dive boat and trying to follow the lines on the tables), logbook, dive statistics, multi-level diving, etc.

If you are going to use the dive tables, you would need a dive watch to keep track of your time underwater. Most "proper" dive watches will cost you more than what an entry level dive computer would cost you so there is no cost benefits at all.

Exception: If you are going to be cleaning boat bottoms in no deeper than 5 feet, there is probably no case for dive computers in this scenario.

As if anyone would need an excuse to buy a dive watch!

OP, I'm a newb so my opinion is probably worth as much as you're paying for it. I'm currently diving the PADI eRDP tables. And while it's fine on a Saturday at the quarry, it is definitely temporary until I've saved up for a good computer. If I was headed somewhere warm and exotic, I'd want a computer to take advantage of as much bottom time as is safely possible.

 

[TMHeimer]

I recommend a simple inexpensive computer like my Puck. You said technically you won't be planning dives, but you must--everyone must. Anyway, I've not been to Cozumel, but assume you're planning on dives deeper than 30' or so. Computer is best for that, plus as mentioned, probably required by the dive op. Keep in mind something almost never mentioned is that tables always give at least a bit more conservatism. The profile is based on your absolute deepest depth, which means you are not really right with your face on the bottom most of the time. Computers track your exact (theoretical, of course) bottom time remaining.
If you go with watch, depth gauge and tables, I can say my most recent $25 watch was bought at Walmart July 2, 2011 and still works (I stop it between dives, so haven't had to change battery yet, which can cause the watch to leak, so I hear). You don't need to have an expensive one with a bezel to set, unless you are incapable of memorizing what time you begin to descend--which in today's world may be a problem for some....
Ask as many questions you can think of by e mail before you go.
Oh, you need not be a very experienced diver to get by without a computer.

 

[Top_Gun]

I just dove Cozumel last November. The dive Op I used didn't require a DC. The dive master leading the dive did have one so we kinda just followed his.

Do you really need one?

I sure hope so..
I just bought one, and it wasn't cheap, but what in this sport really is?
No,it's not a Shearwater..I wish

 

[dmaziuk]

Say they charge $10/day for computer rental. The cheapest Puck is now $150. So if you dive with shops that require a computer, you'll pay them the price of your own in 15 days of diving. That's an if of course: so far I've been on boats where we wrote down max. depth and time in the boat log after the dive (and end pressure of course, but that a different gauge), but nobody actually said anything about computers.

OTOH when they see one on my wrist, they don't need to ask. Who knows what they'd do if it wasn't there.

 

[halocline]

You don't technically 'need' a dive computer, but you do need a way to track your N2 loading, and your depth, and your dive time, and a dive computer makes that very easy. But, if you already have a dive watch, analog depth gauge, a smartphone, a slate, and enough discipline to stick to a plan, you could plan your dives with inexpensive software on the smartphone and dive the plan.

If you do not have a watch and a depth gauge, it's going to be much more cost-effective to just get an inexpensive computer. If you're renting gear, you could either buy a wrist computer or rent a console with one.

If you're thinking "I can just follow the DM" that's not a good idea at all. You don't have any idea what he's actually going to do and your specific dive profile will be different anyway. If it was one shallow short dive/day, that could easily be done with tables. It's the repetitive dives with multi level profiles that you get screwed on with the tables.

I guess there is one other option if you're really set against buying a computer. Get the old padi wheel and learn how to use it. You can probably find one on ebay for practically nothing. I use one for back up in Cozumel. It's not the most accurate device in the world, and I bet it's not even part of the current padi training. But it does allow for some multi level planning.