Do I want redundant gauges with dive computer?

[LeadTurn_SD]

I've now got everything I need except for gauges/dive computer. If I buy a hoseless AI dive computer, do I still want to get a console depth indicator/SPG/compass (possibly nice small size) to act as a backup?

I've read you should have backups, but what do people actually do in practice? I've been thinking that it would be great with an A/I wrist mount dive computer to have fewer hoses, but I guess if I'm using the console as a backup, I can clip it on the left side of my BCD and pretty much have it out of the way, unless the computer konks out.

In case it matters, assume purely recreational diving, and most likely not below 60'.

(My OW ocean dives just got held up until June, was supposed to be next week, so now I've got several weeks of "shopping time" on my hands...)

I highly recommend an analog backup for all critical data: depth, air pressure, time. So even though I have a computer, I also dive with a dive watch, analog depth gauge, wrist compass, SPG. I also carry a dive table and slate with me. If doing multiple dives, I record (on a slate) max depth and bottom times, and make a mental note of max NDL's for the planned dive (but also have this writen on the slate in my BC pocket in case I have a "senior moment" during the dive ). This way if the computer croaks during the dive, we can in most cases continue the dive via conservative "old school" analog methods.

This is all may be "overkill" on redundancy, but I act as the "dive master" for my wife and kids on our shore dives, and need to be sure the dive we are doing stays safe....

Safe Diving!

 

[Web Monkey]

I've now got everything I need except for gauges/dive computer. If I buy a hoseless AI dive computer, do I still want to get a console depth indicator/SPG/compass (possibly nice small size) to act as a backup?

I've read you should have backups, but what do people actually do in practice? I've been thinking that it would be great with an A/I wrist mount dive computer to have fewer hoses, but I guess if I'm using the console as a backup, I can clip it on the left side of my BCD and pretty much have it out of the way, unless the computer konks out.

I bring a ScubaPro mini-spg/depth gauge and cheap dive watch with me and leave it in my bag. It has the same quick disconnect as my SmartCom, so if my computer fails, it just means the dive is over, and I can swap it for the next dive.

Unless you're doing some sort of overhead enviroment (deco obligation or actual overhead), there's no reason to bring both a computer and a backup on the dive.

Every bit of extra cr** you bring underwater is more drag and something else to snag, break or lose.

Also, even if your computer failed and you had an SPG and depth gauge (and tables) with you, it would all still be useless, since there's no way to figure out where you should be on the table unless you also happened to know how long you had been down and what your max depth was and which group you were in from any previous dive(s).

A spare on the boat is nice, but I never bring it on the dive.

Terry

 

[shoturtle]

I've now got everything I need except for gauges/dive computer. If I buy a hoseless AI dive computer, do I still want to get a console depth indicator/SPG/compass (possibly nice small size) to act as a backup?

I've read you should have backups, but what do people actually do in practice? I've been thinking that it would be great with an A/I wrist mount dive computer to have fewer hoses, but I guess if I'm using the console as a backup, I can clip it on the left side of my BCD and pretty much have it out of the way, unless the computer konks out.

In case it matters, assume purely recreational diving, and most likely not below 60'.

(My OW ocean dives just got held up until June, was supposed to be next week, so now I've got several weeks of "shopping time" on my hands...)

Decor Supreme

SPG, compass and depth gauge. It is very compact. I have a Aeris T3 wireless, but have this gauge as a back up. It a good idea, you never know when a battery might fail.

 

[jcscuba]

David: I use the same gear you want to purchase. I've never had a problem, I see some divers carry an extra pressure gauge, but that kinda defeats the purpose of wireless. I use an additional Casio Hyper Aqua, in the event the computer should crash, it would show me my depth and time for surface interval. I'm not personally worried about running out of gas, I tend to go upward as soon as I hit the yellow. Hope this helps cj.C.

 

[highdesert]

I'm not particularly fond of AI computers as the wireless link has the potential for too many failures for very little benefit.
Shane

... a bit confused here ...

Am I missing something? We have AI computers, but they are not wireless. They live at the end of a HP hose, just as any console gauges would. Your statement sounds like AI computers are by definition wireless.

Our computers are also prone to failure, just like anything else you take below with you, and don't solve any redundancy issues, but we feel like there's less likelihood of failure than with a wireless unit.

 

[micklock]

An AI computer uses a transmitter so you don't need a hp hose.

 

[shoturtle]

AI means air integrated computer. You can have it with a hp hose or a wireless transmitter. They are both AI.

 

[ChrisA]

I've read you should have backups, but what do people actually do in practice? I've been thinking that it would be great with an A/I wrist mount dive computer to have fewer hoses, but I guess if I'm using the console as a backup, I can clip it on the left side of my BCD and pretty much have it out of the way, unless the computer konks out.

In case it matters, assume purely recreational diving, and most likely not below 60'.

(My OW ocean dives just got held up until June, was supposed to be next week, so now I've got several weeks of "shopping time" on my hands...)

Are you just strarting out buying gear? If so just skip the computer. Or at least hold off a while before buying one. Believe me it is unlikely for a beginner who plans to stay above 60 feet to bump into NDL. You will run low on air first. Can you really make a tank last 60 minutes at 60 feet? I'd bet "NO". You will do fine using tables for a while

So buy the "backup" gauges first. Then later after you have a few dives logged buy a computer. But I'll still bet that if you are at 50 feet NDL will not be an issue.

Later as you gain experiance you will go below 60 feet and yo will begin to breath a bit less air I is easy to zip on past NDL at 110 FSW. but that will not be you first few dives.

About backups. I have a mechanical SPG clipped to the d-ring at the left hip. and I use a very simple wrist computer. If my computer fails it is not a big deal. My computer's battery has failed and we just complete the dive. But if the SPG fails it's "thumbs up" I dont need backups. But if my SPG was a wireless computer I'd have a backup. Those things screw up frequently

I don't really see the point of an AI computer except after you get home. It is fun to plot air consumption of the computer But it's not rocket science to record time and pressure on a slate if yo need to compute SAC.

 

[davidbaraff]

Are you just strarting out buying gear? If so just skip the computer. Or at least hold off a while before buying one. Believe me it is unlikely for a beginner who plans to stay above 60 feet to bump into NDL. You will run low on air first. Can you really make a tank last 60 minutes at 60 feet? I'd bet "NO". You will do fine using tables for a while

So buy the "backup" gauges first. Then later after you have a few dives logged buy a computer. But I'll still bet that if you are at 50 feet NDL will not be an issue.

I'm thinking about doing exactly that. No, I can't make a tank last 60 minutes. But in August I went boat diving in Kaui, and on a 50' dive (yeah, they should have held me to 40', but it was my second day diving with that group, and I guess they could see I was doing reasonably OK) I was down for around 35, maybe 40 minutes. (I'm not certified yet, but those two dives were ocean dives #5 and #6 in my lifetime.) Now, it was a two tank dive, and I'm pretty sure the surface interval couldn't have been an hour. And I know for a couple of minutes I was at 55' feet.

The second dive was pretty much the same conditions.

Now, if I was using NAUI tables, wouldn't the above be "illegal"? But I'm betting with a dive computer, it would come out fine. So, it sounds like for warm water dives in Hawaii, given that I'm only going to be going with a DM/charter group in the forseeable future, and given that they don't want to string the dive out all day, this kind of two-dive activity seems to be the norm.

Of course, if I've made a grevious computational error in the above, please feel free to point it out. But it feels like I'm already kind of close to needing one...

 

[diver_paula]

I'm major proponent of backup gauges. When I bought my first computer I kept my analog gauges. I later went to two computers. I won't go on a charter weekend and especially a weeklong SCUBA trip without using both. If one flips out, runs out of batteries, or the like I can still continue to dive. The backup computer will have all my info. I recently went AI but decided not to use a backup SPG. Same as other posters have said - the computer SPG fails and the dive ends.

Paula