For you boaters...
Google Boat+LPG or Boat+Propane or Boat+CNG...
You will find in Europe firm in the business of converting pleasure boats to these cheaper fuels. Yes availability is a problem.
However, if we can ever vote this socialist out of office, their is no telling what technological advances will not be still born or will advance without the threat of even bigger government messing with their business plans...
Dude, there is NO WAY I would go out on the Lake (Lake Of The Woods) with 70 gallons of liquid Propane on board!
The way a gas leak would end up, is just a smoking hole on the water. No thanks, that would not only be dangerous, it would be stupid.