Scooter and Gas Planning

[GLENFWB]

Since completing my cavern class...I got to wondering how you do gas planning when a scooter is involved? I don't ever plan on using a scooter, but I am just curious. Do you have to plan for a scooter and gas failure at the farthest point? How do you know how much gas it will to take to swim out when you scootered in? Just wondering how you guys who use scooters do gas management?

 

[TSandM]

I don't scooter in caves, but my understanding is that if you are going far enough in to be dependent on a scooter to get you out, from a gas management standpoint, you bring redundant scooters.

 

[karstdvr]

The biggest mistake people make is they make assumptions without testing them. Typically 1/5 for penetration can be good,but may not be ideal depending on other variables based on depth,silty etc. The best thing to do is follow the rule of go no further than what you have swam,and test the exit by swimming out.

 

[Meng_Tze]

You bring enough gas to swim out. If you know how fast you can swim out of a system (say from 2000ft or so), you can calculate how much gas and time it will take from 4000, 5000 ft. Then you add a margin of safety for delays and increased SAC and thus extra deco gas as well.

I also test my swim rates at least twice/year.......

 

[karstdvr]

You bring enough gas to swim out. If you know how fast you can swim out of a system (say from 2000ft or so), you can calculate how much gas and time it will take from 4000, 5000 ft. Then you add a margin of safety for delays and increased SAC and thus extra deco gas as well.

I also test my swim rates at least twice/year.......

The unfortunate thing is people make assumptions using calculations,but never test it. I hear so many people who say that I can make it from the Heinkel on an AL80,but this was based on calculations that don't take into account many factors. Unless it is tested in each specific cave,then it is a guess,which you are betting your life on. About 10 years ago there was an exiting DPV diver who guessed wrong at Ginnie,and if it wasn't for finding an entering team on the main line,he would be a statistic. There have been many near misses due to assumptions that "my buddy can tow me out",a skill never practiced,then you have two people in jeopardy.

 

[Dive-aholic]

Some divers only breathe off their stage bottle when scootering and reserve back gas for emergencies. Others plan for failures. I have gone 2500' into JB on a scooter, turned and swam out on a stage while pushing the scooter ahead of me. I made it. I'm sure I could make it with even more air with leaving the scooter in the cave, which I would do if needed. I also use the scooter to get me to places where I want to swim to check things out. Again, I plan for that leaving more than enough air reserves for a swim out.

 

[GLENFWB]

All interesting replies....thanks for the insight. Like everything else in cavern/cave I hear you guys saying that you plan for worst case scenarios when scootering....if you are smart that is.

 

[jeandiver]

All interesting replies....thanks for the insight. Like everything else in cavern/cave I hear you guys saying that you plan for worst case scenarios when scootering....if you are smart that is.

Another way to do it is not use a scooter.
Like some of us old peeps.

Seriously , those that scooter that I hang around with , DO plan for worst-case.

"Oh Lord , keep me prudent , ALWAYS Prudent !"

Jean

 

[Mike Edmonston]

Another way to do it is not use a scooter.
Like some of us old peeps.

Seriously , those that scooter that I hang around with , DO plan for worst-case.

"Oh Lord , keep me prudent , ALWAYS Prudent !"

Jean

2:50 AM

Couldn't sleep Jean? Or did you just get back in from a trip?

Safe Diving

 

[tflaris]

I only scooter where I have swam before and have an understanding of a min level of gas supply needed to get out and then multiply by 1.5.

Risk versus reward