Originally Posted by kerry

In the 90's my school had a large tech program teaching fleet mechancis how to do CNG conversions. Lots of utility companies were doing it but I assume they all had fueling stations in their yards and their trucks didn't travel more than one tank of fuel distant from the station.
Some marinas have CNG pumps because some sailboaters prefer CNG over propane because natural gas is lighter than air and wont sink into the bilge and cause an explosion like propane.
CNG tanks are quite different than LPG tanks. Most CNG tanks I have seen have an external layer of fiberglass.