Kathy & John, I am planning to take my 50' trawler down to the South Pacific next year. I have dived since 1967 so the idea was to dive our way across the South Pacific and maybe find a spot no one has ever dived before. I did extensive research into compressors that could be installed aboard a boat. The best and most highly recommended is the Bauer Junior II (http:// www.bauercomp.com/norfolk/breathingair/scubadiving.htm). It is the most reliable but costly: approximately $8500 for the unit not including installation. The Max-air 35 (http://www.max-air.com/) is quite a bit less but has a reputation for being finicky. I had planned to use 220VAC to power the compressor which the companies say have as much as 50 amps startup. These compressors come in a variety of power options including gasoline engines. What I decided to put on my boat was the largest of the Brownie (http://www.browniedive.com/) SSA (surface supplied air or hooka) units, the Brownie 390. The cost is less than $3000. There is no installation as it comes complete and it takes up far less room than a compressor. It will support two divers down to 90' and four divers down to 60'. I figure than this will be adequate for 90% of all my diving requirements, everything except overhead environments such as caves or wrecks. For the rest of my dives, I keep four tanks and gear on board and fill them anytime we get near a dive shop. It is interesting to note that the equipment that covers 90% of my dives takes up less room than the equipment for the other 10%. Phil Eslinger Flat Earth N50 Ko Olina, Hi.