Do most site shops have air fills? It would be nice to double-dip at sites, bring my own tank for dive 1, and get it refilled on surface break.
Cas Abou/Bdiving No. They have a fill truck come periodically.
Dive shop on the beach at Lagun Yes.
Gowest Yes.
As I think I mentioned elsewhere, you get more than a tank when you rent a tank from the op on the beach. Usually have rinse tanks, drying racks showers, local info and great tips for the dive and a secure safe place to leave your stuff.