Diving Without Depth/time only SPG

[OldNSalty]

Back in the early 70's, there was a guy that would dive with only a SPG. I did a deep ( 150+ ) dive with him. BTW, he could freedive to 100+ feet and spear three fish on one breath. He would tow his small dory around the island. He would fight off the sharks if they wanted the fish on his spear.

He would simply go as deep as he wanted or could til his SPG hit 2000 PSI, then he would head up.

Amazingly, he is still alive. He is a legend in his own time. He was an animal.

Would I recommend this practice? NO!

However, I did learn from it. Head up when your tank hits 2000 PSI on a 3000PSI tank. Do not continue your decent.

If new divers followed this procedure, then they would stay within their 40' to 60' depth limit.

That is not to say, keep going down if you still have the air ( gas ). You need to have a dive plan and stay within your limits.

You need a dive computer and know how to use it.

We actually have been requiring dive computers on our trips since 1990. On a once in a Once-in-a-lifetime trip, we highly recommend that you dive with two computers and redundant air supply monitors ( SPG, Air-integrated computers ).

I applaud your use of the internet and an informative post without any unnecessary self promotion of dive gear.

 

[James R]

try reading the post again. I DON'T CARE HOW YOU CONFIGURE YOUR GEAR. i don't care if you choose to take your doubles to the comal. and i would not think you are fos if you did.

I read your post more than once. If my computer shows me how much air is in my tank, then it may be worth while no matter the depth, don't you think? Why don't you re-read your own post, here it is to save you some scrolling:

for whatever reason you want your computer along on a 15 ft dive.

Also, why do you keep bringing up fos? Is it because I used it earlier in the thread? I wasn't referring to you when I used that acronym, but whatever...this is ridiculous.

 

[ianr33]

You need a dive computer and know how to use it.

No you don't.

We actually have been requiring dive computers on our trips since 1990. On a once in a Once-in-a-lifetime trip, we highly recommend that you dive with two computers and redundant air supply monitors ( SPG, Air-integrated computers ).

Do you sell these by any chance?

Your posts are getting tedious.

 

[TSandM]

I think it's fair to say that any time you know without a doubt what your maximum possible depth on the dive is, and it's shallow enough that your air supply will not permit you to approach the end of your no-stop time, the only instrument you truly NEED is a pressure gauge.

Any time those two criteria cannot be met, you need a method of measuring depth, and a timer.

If you are doing a once-in-a-lifetime trip, where you don't want to miss a single dive, having a spare method of measuring depth and time is a good idea. Since dive computers will generally give you more bottom time than tables will (unless you are doing very square profiles), a dive computer is not at all a bad idea for such a trip, and if you take one, taking two makes sense. Remember that both of them have to go in the water with you on EVERY dive!

(So I don't think beaverdivers, in this case, is saying anything that isn't pretty darned valid.)

 

[ianr33]

I
(So I don't think beaverdivers, in this case, is saying anything that isn't pretty darned valid.)

I'm guessing you don't dive with "redundant air supply monitors" though?

 

[RonFrank]

It's a pointless discussion. All divers I have been with dive with a SPG, and/or Computer and/or a BT but some way to measure gas, time, and depth. Have I ever dove without these tools? Yes, but because my computer flooded and I was not wearing any backup. So for one dive no depth or time. I knew the site (hundreds of dives there) and knew exactly the profile we were going to do. So I did my dive like always but followed rather than lead, and kept an eye on my air as it was an indicator of time which my buddy was watching anywho. Having a buddy is handy!

I have backup computers and SPG's so my down time is nill. I should really carry the backup computer, but I am rather comfortable with my profiles when diving close to home. So I have no fear of losing my puter and switching to my backup. On a new site/vacation I carry two computers as I am often hitting the NDL at least once or twice a day.

So would I do a dive without my computer....yes I would and have. Would I make a practice of this.... I do not and will not. Would I dive with a trusted buddy if my computer floods? I have and would again.

 

[Kevrumbo]

From the other thread ("Depth Awareness"):

No . . .it is not impossible to figure out depth without a depth gauge! At the very least you need a watch and a SPG --as well as knowing what your surface consumption rate (SCR) is. . .

Example: My SPG for my 11L Tank (AL80) shows 160 bar in five minutes down from 200 bar full tank --or a delta consumption of 40 bar/5 min. Simplify this depth consumption rate (DCR) to 8 bar/min. I know my surface consumption rate (SCR) for the 11L Tank is 2 bar/min. Therefore DCR divided-by-SCR will yield a factor equivalent to the approximate depth you're at in Atmospheres Absolute (ATA) -- so 8 divided-by 2 equals a depth of 4 ATA.

And finally, 4 ATA easily converts to meters depth by subtracting one and multiplying by ten: 4 minus 1 equals 3; 3 multiplied-by 10 yields 30. Hence you're approximately at a depth of 30 meters (same as 100'). . .

 

[MaxBottomtime]

I did not get a dive computer until I had over 400 dives. I began diving with a steel 72 with a J-valve. I could have very easily dived without any instruments at any number of my local dive sites. Many are less than 40 feet deep and the 72 would not last a new diver enough time to get close to my ndl. I prefer diving with a computer or at least a watch, depth gauge and spg but I could easily make a shallow dive without them if needed.

 

[dumpsterDiver]

I dive all the time in shallow areas without turning on my computer. I want to save the battery. I don't need to know the time and if the depth is inconsequential, I do not need a guage for it. in many situations I would rather dive without a computer/timer/depth guage than without a compass.

Many years ago, our work regulators only had pressure guages. no depth, no compass and this was before computers. A night beach dive, with no possible way to exceed 30 feet.... I got completely turned around and my buddy and I got low on air, came to the surface in a thunder storm, checked our location (1/4 to 1/3 mile offshore) and then re-descended and booked "in" across the sand ridges toward shore until we were completely out of air.

We came up when it got hard to breath and we find that we got turned 180 degrees on decsent in the dark and had been swimming straight offshore for the entire time. We were now well over 1/2 mile out and had a 60 minute swim in on the surface. I swore I would never dive again without a compass.. Depth guage .. meh..

 

[DiveNav]

Is this a safe practise?

Most of the time NO ... specially for a new diver.
Get a dive computer or a bottom timer ... they are not that expensive.

Alberto (aka eDiver)