Charlie99:Or don't go the route of trying to have one bag fulfill two different sets of requirements.
Solid, well made suitcases are reasonably priced, and can hold all your dive gear + all the other stuff you travel with.
A lightweight, low cost non-wheeled duffle bag with nylon zippers does a good job of taking gear to and from the boat, and not taking excessive space once you've setup your gear.
One of my pet peeves are people that show up on boats with huge wheeled duffle bags that don't fit under the boat benches and take up a lot of space. The only thing more obnoxious is people that litter the deck with large rubbermaid containers.
I agree with Charlie. Get a nice travel bag for your gear that you can also put clothes, etc in...and then make sure you have a good mesh equipment bag for the boat...meaning leave the wheely bag at your hotel! The big wheeler bags on the boats are cumbersome, take up too much space and can be a safety hazard if there's no way to properly store them.
I recommend Stahlsac, Armor and Scubapro bags.