I agree with Blades that the 13 cu ft tank is too small to deploy for rescue work and that larger capacity tanks is the real answer. Larger capacity tanks are now available for front mount systems that are double the capacity of the 13 cu ft, specifically the 27-30 cu ft steel tanks. These tanks still have maintain a compact profile, but have ample life support for shallow water operations. Coupled with a bail out, you are looking at close to 50 cu ft of air. With all chest mount dive systems, a traditional full size (63,80 cu ft, et) back mount tank capability for additional life support is still needed.
Storage space is a premium for dive rescue professionals and was the key factor in the development of a compact dive rescue system. Speed of donning is secondary to having the space to store a deployable dive rescue dive system in the first place. The reality became either we (rapid dive rescue professional) have a compact dive rescue system that we can carry with us, or we show up to a scene without any dive rescue capability. It should be noted that the Rapid Diver system was developed/evolved by PSD professionals that needed a compact dive system that would fit in their vehicle whether it be a patrol car, rescue boat, helo, or even full size fire/rescue trucks for first-on rapid dive rescue response.
The Rapid Diver system is the only fully patented and trademarked chest mount dive system and is now the gold standard for rapid response dive rescue professionals. The Rapid Diver was first introduced at DEMA in 2005 and comes with a 27 cu ft steel front tank as standard and with a full size back mount tank capability on the back pad (50,63,80 cu ft, et). There are 1000's of units deployed since it's introduction in 2005 and has been used in many successful rescues. The Rapid Diver was the dive rescue gear of choice of the Long Beach Fire Dept Dive Rescue Team during Travis Pastrana's world record jump off of the Long Beach Pier New Year's Eve.
The type of dive rescue scenario the Rapid excels at is the rescue of occupants of vehicles that find their way into shallow water (less then 10'). In situations where the occupants are unable to open the door/window to get out safely. There are approximately 1500 water related vehicle accidents a result in 600 drowning's per year, most in 3 ft or less from the surface.
I can quote one Fire Chief (Captain) that now has a fully equipped dive rescue capability, that said "If you show up to a water event without a dive rescue capability, you are not honoring your oath of rescue".
2009 was a great year, and I am looking forward to assisting the more teams enhance their dive rescue capabilities in 2010. If you have any questions, or want a list of dept's using the Rapid Diver system, feel free PM me directly.
Chris