It all depends on where you intend sailing, for how long your sailing excursions will be and how often you intend
diving. No use lugging 2 or 4 pre-filled bottles along if you are planning a 4 week
diving trip. If you intend visiting
remote parts of the world, you have to be fully prepared. We have a Bauer Mariner 320 (big compressor) on board, we love
remote islands, we dive often and we are very happy with our setup. We also often fill
tanks for other yachts on barter|trade deals and thus making it more cost effective.