How can people car pool cheeper across water?

Question

their are cars that drive on land and underwater, so why not buy these kind of cars and carpool to work instead of taking the ferry. maybe neighbors or co-workers. all each buy one and take turns driving. or maybe your company will help or our communities, government help.even though this state gets about 37cents a gallon and dont care about cutting the gas for anyone.

Answer 1

Amphibious cars (which go ON water, not UNDER it...though ...did Rinspeed ever finish their submarine car?) are all:  

Old and rare (and therefore expensive to maintain), and usually expensive

or

New and expensive.  

Also they mostly aren't terribly fuel efficient.

That is why not.