Yes, I used a steel tank. Well, I looked for places one day in advance and my wife had to call many places before finding an opening with these guys. Id try and book at least 2 or 3 days in advance.
Btw, thanks for the okinawa dive info. I only spent a day and a half ‚â€Âhere and didn:t have a chance to dive there. When I go there again, I plan to go in the fall so I have a better chance to see manta.
chris