Scooter planning in caves

[KMD]

RTodd,

I guess this is a side question related to scooters, but may fit more in with general philosophy of dive planning.

When figuring out a dive plan with a scooter, how many major failures do you take into account?

Examples:

I want to reserve enough gas to get back if a scooter fails - 1 major failure

I want to reserve enough gas to get back if a scooter and OOG occurs - 2 major failures

I want to reserve enough gas to get back if both scooters and an OOG occurs - 3 major failures.


Obviously as the number of failures increases in your planning, the amount of gas needed increases. Probably to the eventual point of not being able to take enough gas with you into the system.

 

[RTodd]

RTodd,

I guess this is a side question related to scooters, but may fit more in with general philosophy of dive planning.

When figuring out a dive plan with a scooter, how many major failures do you take into account?

Examples:

I want to reserve enough gas to get back if a scooter fails - 1 major failure

I want to reserve enough gas to get back if a scooter and OOG occurs - 2 major failures

I want to reserve enough gas to get back if both scooters and an OOG occurs - 3 major failures.


Obviously as the number of failures increases in your planning, the amount of gas needed increases. Probably to the eventual point of not being able to take enough gas with you into the system.

Enough to always get out. Planning depends on distance, cave type and ability to exit in an emergency, number of team members (and consequently the number of scooter failures), etc. Your first priority should be planning gas so that an actual sharing situation (other than temporary while it gets sorted) is highly unlikely since this really slows the team down and on scooters forces the out of air diver to tow the donor even if all scooters are functioning. Hence, reserving all backgas which gives you the ability to pass off stages to a buddy that somehow loses his back gas and use your backgas so each member exits independently.

Second priority is having enough scooter to exit without a tow. This depends on the logistics of the dive. On shorter dives, towing a buddy in an easy cave some distance is less of a big deal if it would also be possible to just swim out. I have been towed out for about 40 minutes. It sucks. Don't plan on ever putting myself in that position again.