Diving Without Depth/time only SPG

[eelnoraa]

I would NOT. But my question is WHY?

 

[Rich Keller]

I dive with a SPG only in areas where I know I cannot get below 33', usually shore dives.

 

[CT-Rich]

I like a simple rig, but a computer is so standard now. Are there dives where I wouldn't abort because I noticed the computer malfunctioned, I suppose so. If you are diving for golf balls maybe you don't need this stuff. Generally, I don't see much point in changing my suit up routine because there is an exceptional situation. I would say these days, your own computer is pretty high on the list of things a Newbie ought to buy instead of renting. Get used to it, trust it, know how to operate it.

 

[adurso]

For the past week my daughter and I have been diving Lauderdale by the Sea, the Blue Heron Bridge, and Venice. All known and shallow, less tha 30 feet.

Her air integrated Suunto Cobra will only give air pressure, it will not go into dive mode.

So we did all our dives sans depth and time for her.

I began diving when J valves were the norm. The lack of modern amenities fills me with mild to waning interest, as it does my daughter.

As long as she could check pressure, all is well.

 

[Rhone Man]

I have done maybe 10 dives in my life with no SPG (although all bar one, I had a J valve - the other was the last time I relied solely upon a wireless transmitter).

 

[CT-Rich]

For the past week my daughter and I have been diving Lauderdale by the Sea, the Blue Heron Bridge, and Venice. All known and shallow, less tha 30 feet.

Her air integrated Suunto Cobra will only give air pressure, it will not go into dive mode.

So we did all our dives sans depth and time for her.

I began diving when J valves were the norm. The lack of modern amenities fills me with mild to waning interest, as it does my daughter.

As long as she could check pressure, all is well.

Realistically, you can do plenty without a lot of stuff. I like my computer and it makes life a lot easier during the dive and takes away a lot of the stupid errors you can make like forgetting to set your watch. It is worth having just so I know time and max depth and how close to the NDL I am, even if I am not going to hit them. I wouldn't sit out a dive that I know could not go anywhere near the NDL, but I think it would bother me. I like watching my gauges, I consider it part of the dive experience and habit of good diving. Computers are so ubiquitus and reliable now, I wouldn't chose to leave it on shore because I know with a 72 and 30 fsw I won't get bent. I also wouldn't take my BCD knife off just because I am going in a pool. It is there because as far as I am concerned it belongs there. One of my purchases for next year is to go to a more sophisticated wrist mounted computer and my current one will stay on the console as a back up.

 

[Kharon]

For myself - a definite NO!. I was taught to get your kit perfected and dive it the same way every time. Even though there are dives where I don't need to carry my pony it's always there. Everything the same every time means everything is where it's expected to be and it's second nature, reflex to use it when needed. Also never anything forgoten.

 

[danvolker]

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 was certified in 72, and did lots of 130 plus dives in 76 and there after.... Even in 76, there were few people with pressure guages..Most of us had steel 72's that would be at 2250 as full..not to say we might not get them jacked higher by the early 90's, but few compressors /diveshops would be able to fill much over 2400 back in the 70's, if at all.

Common was the J valve instead of pressure guage, so you would run out 30 minutes to 60 minutes into the dive( depth depending), and then pull the j valve and have a 500 psi reserve to get to the surface with, at the speed of your smallest bubbles. Some would opt to shoot one more fish, then free ascend on actual OOA status. Both were common.

Depth guages were pretty common, but not everyone had them....and a dive watch with rotating bezel for elapsed time WAS extremely common. We did know the tables, the NAvy tables, and were aware of them for all dives....time and depth were always considered, like 60 feet for 60 minutes.

Today I consider a computer nonsense....I use a computer in guage mode, and it looks more like a watch. I use my tables, and don't have to worry about a "redundant" computer.

You would be shocked at how many divers were doing 70 to 100 foot deep dives back in the 70's, and on pulling the J, did the ascent at bubble speed to surface, without stops.....In the 70's, I had never actually heard of any divers any friend knew, that had ever been bent. Just saying, some of what here you hear today is real science, some of it is the push to sell gear and more.

 

[dumpsterDiver]

I was certified in 72, and did lots of 130 plus dives in 76 and there after.... Even in 76, there were few people with pressure guages..Most of us had steel 72's that would be at 2250 as full..not to say we might not get them jacked higher by the early 90's, but few compressors /diveshops would be able to fill much over 2400 back in the 70's, if at all.

Common was the J valve instead of pressure guage, so you would run out 30 minutes to 60 minutes into the dive( depth depending), and then pull the j valve and have a 500 psi reserve to get to the surface with, at the speed of your smallest bubbles. Some would opt to shoot one more fish, then free ascend on actual OOA status. Both were common.

Depth guages were pretty common, but not everyone had them....and a dive watch with rotating bezel for elapsed time WAS extremely common. We did know the tables, the NAvy tables, and were aware of them for all dives....time and depth were always considered, like 60 feet for 60 minutes.

Today I consider a computer nonsense....I use a computer in guage mode, and it looks more like a watch. I use my tables, and don't have to worry about a "redundant" computer.

You would be shocked at how many divers were doing 70 to 100 foot deep dives back in the 70's, and on pulling the J, did the ascent at bubble speed to surface, without stops.....In the 70's, I had never actually heard of any divers any friend knew, that had ever been bent. Just saying, some of what here you hear today is real science, some of it is the push to sell gear and more.

Yeah but... if you followed the Navy Tables (and the directions that came with them) then they were not all that aggressive.


For example, didn't you HAVE TO go to the next greater depth and time increment when spearfishing (since it was a strenuous dive). Also, weren't many of your dives back then floating high above the bottom and dropping down for short durations to get a fish... thus, the square profile assumption was another significant factor in making the tables conservative. I know i can dive for much longer on my computer than on Navy tables for the typical dives that I do.

 

[beaverdivers]

Today I consider a computer nonsense....I use a computer in guage mode, and it looks more like a watch. I use my tables, and don't have to worry about a "redundant" computer.

Dan, do you use redundant gauges or devices; watches, bottom timers, j values, SPG, depth gauges?

If you are doing a 100' dive, then do you head directly to the surface at 60'/min. after 20 minutes of bottom time.

In 1989, I had a group diving Bloody Bay Wall off Little Cayman. Our protocol was that you were either on the dive tables or a dive computer. Midway through the trip, one of our divers using dive tables said " This dive was great, but all you computer divers were down an hour and I had to be back on the boat in 30 minutes! "

Dive table divers wanted to shadow divers with computers. Our protocol is every diver must have their own computer.

After that trip, we decided to draw the line and require dive computers. The decision was not retail driven, it was driven by the desire to spend more time U/W with less risk.

If you figure your cost/minute of diving, a dive computer will pay for itself in one dive trip.