CNG a the airport of all places.....
We recently went thru finding a place to refill our CNG for the first time. After a website that was pretty useless (sounds like the same one), we ended up talking to a guy at AVSG, which is a local gas company with a location at Logan Airport. He actually came to the marina, picked up the tank, filled it, brought it back, and charged us only $25. I have no clue if the major aiport near you will have a gas company around that supplies various needs. AVSG isn't in business becuase of the demand that a few local Hunter owners with CNG stoves create, however, they can fill our tanks. Once you find the CNG, you can relax and know that with only minimal opening and closing of the hatch, you aren't gonna blow your boat apart because of a small leak. It's worth the effort I think. Good Luck