I always bring my own gear except for the tank and weights. It all weighs in at less than 40 pounds. (Mask, fins, BC, regulator, wet suit) I bring my dive camera, strobe and housing as my carry on. Two bags will usually cover all my stuff and give me some extra room to carry some of my wife's stuff.

You are correct about most local airlines treating scuba gear special for inter-island hops. We have been to Fiji on a few dive trips and they usually do not count that as luggage between islands. However, we did have to get on scales to make sure we all would make it on the plane.