Talked to Sure Marine awhile ago telling me they shut the system down last January. He had his own compressor for filling tanks to 2500 PSI, unlike the local fuel stations that fill to 3600 PSI. Process was becoming too expensive, plus the compressor needed a rebuild. He still has it if someone wants to pick it up.
So it seems that upgrading our boat to propane is becoming more likely. Seaward sold their business to Whale and Sure Marine bought all the remaining conversion parts except for the oven. I can convert our Seaward Hillerange top burners to propane, but not the oven. If I can find a used Seaward propane stove that still works, I can use the oven burner from it in to replace the CNG burner in our stove. It may just make more sense to go all new. Trident makes a two eleven pound bottle locker that will fit in our starboard lazarette locker. Expensive, but more convenient than trying to fill our CNG tank.
If someone has a better idea, please let me know. I'm all ears. Maybe time to start a, "Go Fund Me", page.
Why not go alcohol? As stated, that is what I am going to do.
I think the tradeoffs in terms of slower cooking and the like are not relevant to me. I don't want pressurized gas of any kind in my boat. I am keeping CNG for now, but will not go to LPG. Would be very expensive to try to put in a proper propane locker. YMMV.