Power Inflator and Elbow Upgrade
I used to have a Watergill (or was it SeaPro) AT-Pac with a unique power inflator. The low pressure hose ran inside the corrugated hose. There was a standard BC quick disconnect fitting at the corrugated hose's elbow. Unfortunately, there was a slight design flaw that caused a leak where the metal male fitting attached to the elbow.
@Akimbo has a picture of a more robust model with a metal, rather than plastic, elbow here:
View attachment 458971
Having the fitting on the top of the elbow or a swivel or both would greatly improve the durability. One could go a step further with a high flow fitting and attach an optional inflator/regulator at the end.
I still have that lp/corrugated hose inflator setup somewhere to fool myself into thinking someday......