Computers - do beginners need them?

[jonnythan]

Uncle Pug once bubbled...

Let me pull the gossamer veil back just a bit here Aaron... not that it is hiding anything...

If this were about complex calculations I wouldn't be in the running.... I hates math.

Do I use a computer at all? Well I am using one right now.... but if you mean while I am diving... no.


For example Shane and I did three dives Saturday... back to back with minimal SI of 5 minutes.
99fsw for 23:40 minutes
78fsw for 16:20 minutes
55fsw for 14:20 minutes
All using EAN32 and a single LP104
We were practing OW free ascents with stops every 10 feet.
We were not using computers.
If you had been along would your computer have allowed you to do these dives with us?

I'm not sure what my computer would do.. but my NDL tables wouldn't.

What's the relevance to this thread, which is about novice divers and computers? Would you have taken a novice diver on these dives?

 

[Uncle Pug]

AaronBBrown once bubbled...
While it may seem perfectly obvious to you what 30ft/min feels like, it isn't to others...they (and myself) are safer with the computer.

... how long have you been using that computer ascent rater monitor that tells you how fast you were ascending?

Have you calibrated your brain yet by watching the stuff in the water?

Surprisingly it doesn't take long for a new automobile driver to get a *feel* for how fast they are driving.... if they are paying attention to such things.

Honestly now.... and please answer this question.... do you go out and practice ascents... honing your skills... doing dives just to practice ascending to a certain depth and holding that depth for a set period of time and then ascending to the next planned stop?

Why not? You practice music don't you?

Yes I have a lot of dives under the transom... but notice that my last dives were all about practice.

30 fpm ascents?!? Why we practice 60fpm 30fpm and 10fpm and even less. (sometimes it is important not to dally between stops and we are finding that practicing the really sloooooow ascents has degraded our ability to get a move on it for the deeper stops so we are going to be spending more time practicing the 60fpm.)

BTW... how long does it take to go from 50fsw to 40fsw at 30fpm?

 

[Soggy]

Uncle Pug once bubbled...

For example Shane and I did three dives Saturday... back to back with minimal SI of 5 minutes.
99fsw for 23:40 minutes
78fsw for 16:20 minutes
55fsw for 14:20 minutes
All using EAN32 and a single LP104
We were practing OW free ascents with stops every 10 feet.
We were not using computers.
If you had been along would your computer have allowed you to do these dives with us?

I don't have a Nitrox certification or a Nitrox computer...

Assuming these dives were on air with less bottom time...I'd have to run it through the profile. My NDL tables say a big no. My computer would probably say no also, but it is 20 miles away, so I can't check. The point is, were you at 99fsw (or close) the entire dive? Most of my dives are swimming down a shoreline, so my dives are infinitely multi-level.

Regardless of whether my computer would allow it or not, what's the point? If my computer didn't allow it, I wouldn't do the dive. It's far more liberal than the tables which are far too conservative.

Honestly now.... and please answer this question.... do you go out and practice ascents... honing your skills... doing dives just to practice ascending to a certain depth and holding that depth for a set period of time and then ascending to the next planned stop?

Why not? You practice music don't you?

Every dive is ascent practice. No, I don't go out and practice just doing ascents. I also don't spend 5 hours a day diving, which I do spend playing the trumpet. Playing a musical instrument is also FAR more difficult to learn and become proficient on than recreational diving. I don't have the time or desire to go out and do free ascents for there own sake. When I go diving, I go to explore, see fish, etc...Ultimately, for the type of diving I do and am interested in doing this type of practice would serve very little purpose. I'm not planning on doing the Doria any time soon, or even anything below 100fsw. Hell, I don't even want to go diving on a boat if there are big waves. If it isn't fun, there's no point to me. This is not to say that if my computer died (which means no depth gauge), I would be "right on" during my ascent, but I'd have some clue. Plus, I would doubt that my buddy's computer/gauge died also, so I _should_ be able to use them as a reference, though that is not always the case.

Have you calibrated your brain yet by watching the stuff in the water?

Calibrated? No...in the process? Yes. I do try to watch the stuff in the water...small particles, small bubbles...and see how they are moving relative to me (or vice versa). Am I entirely successful...probably not, but I'm working on it.

 

[MikeFerrara]

If I don't practice, heck...if I'm not careful even though I do practice, my ascents tend to be too slow (when a specific rate is required). A left over from when slower was better for all the dives I was doing. I don't know what the computer has to say about it. During an ascent I watch something (stuff in the water or whatever else is handy) and audit my rate by a simple calculation based on depth chang and elapsed time.

60 ft/min would be 1 ft/sec so...30 ft/min would be 1 ft/2 sec so...hmmm...I think it would take 20 sec to ascend 10 ft at 30 ft/min

 

[raxafarian]

AaronBBrown once bubbled...


I don't have a Nitrox certification or a Nitrox computer...

Assuming these dives were on air with less bottom time...I'd have to run it through the profile. My NDL tables say a big no. My computer would probably say no also, but it is 20 miles away, so I can't check. The point is, were you at 99fsw (or close) the entire dive? Most of my dives are swimming down a shoreline, so my dives are infinitely multi-level.

Regardless of whether my computer would allow it or not, what's the point? If my computer didn't allow it, I wouldn't do the dive. It's far more liberal than the tables which are far too conservative.

I think your computer would be more conservative than tables...

 

[Soggy]

raxafarian once bubbled...


I think your computer would be more conservative than tables...

Yes, given a single level dive, you are correct.

I meant that were I doing a multilevel dive that had 2 minutes at 61 feet, the NDL tables tell me that my entire dive was at 70 feet.

 

[raxafarian]

AaronBBrown once bubbled...


Yes, given a single level dive, you are correct.

I meant that were I doing a multilevel dive that had 2 minutes at 61 feet, the NDL tables tell me that my entire dive was at 70 feet.

I'm guessing UP would not treat a dive with 2 minutes at 70ft and 40 minutes at 40 ft. as a 70 ft dive.... maybe adjusting his 40ft NDL accordingly... but I think that isn't being condoned... just food for thought


IF you are gonna buy a new computer... make sure it has a gauge mode... that way, if you get into more advanced... technical diving, or even for the type of dive series posted above by UP, you won't be waiting for your computer to stop being mad at you.

 

[Uncle Pug]

jonnythan once bubbled...
Would you have taken a novice diver on these dives?

EAN32 precludes that.... as do your NDL tables or RDP.

The relevance is that computers are not necessary to do repetitive dives.


BTW:
Even if these dives had been a square profile (which they obviously were not since we were practicing ascents and stops) and considered as one contiuous dive... at NO point did they cross over into a deco obligation.

 

[raxafarian]

decoplanner likes that 3 dive series just fine... rounded all times up to the minute. Calls for a 1 minute stop @20ft. on each dive.

 

[Soggy]

raxafarian once bubbled...

I'm guessing UP would not treat a dive with 2 minutes at 70ft and 40 minutes at 40 ft. as a 70 ft dive.... maybe adjusting his 40ft NDL accordingly... buy I think that isn't being condoned... just food for thought

Yeah...but I don't have the training or the gonads to question the tables.

At the end of the day, for me a computer is a better choice as it comforts me and holds me and...oh wait, that's not the computer...

I like my computer because it tells me how much time I have at depth based on my N2 levels and also based on how much air I have left. This helps me control my breathing. When I start a dive, it'll say I have like 25 mins of air at 20 ft...so I focus on breathing and bringing that number up. I have seen the number go to 75 minutes within a couple minutes. I try to steady my breathing throughout the whole dive and it gives me the immediate feedback I need to determine how much longer I can stay. I still try to use the rule of thirds, but this certainly helps. It also helps me ascend safely. In addition, it allows me to plan dives, keeps track of my surface intervals, etc, etc, etc.

I'm sticking with it. My recommendation for a new diver is to do whatever fits your finances and your comfort level.