6 liters/min is an insufficient flow rate for DCS treatment.For a recreational diver going on their own or buddy's boat, something like this might be good to have as an all-in-one emergency backup:
Rapid Oxygen R15 Emergency Oxygen Delivery System ROR15
The RAPID OXYGEN: R15 Emergency Oxygen Delivery System is a revolutionary delivery system providing 100% humidified oxygen to victims in emergencies who are having trouble breathing and require 911 assistance. Unlike oxygen cylinders (comprmdmaxx.com
15 mins duration is an insufficient endurance for off-shore use.