My Sabre is equipped with the original CNG and I have a spare bottle. On Maryland's Eastern Shore there are two CNG exchange locations convenient to me. When the bottle installed in the boat is running low I exchange the empty which has been in storage so I have a replacement ready when the onboard bottle runs out.
There is always one bottle installed onboard, held in place with two very substantial brackets. The gas valve is only open when cooking and then closed after use. We never cook underway so the valve is always closed when sailing.
Soon I will take delivery of my new to me Catalina 387 which is of course propane...I'll let you know which I like better, but I've not been unhappy with CNG.
Catalina 387 #29
Rock Hall, MD