Like Jerry said, just keep pluggin away. Regardless of skill level and no offense to yours, their are company's who just need billable bodies. Because of OSHA requirements you have to have a full crew to run dive ops. I know it sounds s***ty but you gotta start somewere. By the way, nothing against Osha standards. I think It should be a minimum FOUR MAN CREW. Then we would all be on a level bidding field and safer. Just my two cents.
There ar quite a few, you just have to look or get on as a deck hand and work your way into the team. With the flooding created by all these schools, it is a know fact that every company has it's own training format and there are just times when they have no room on projects for newbies. Too many rookies want work, but they want it at their convenience and owners and PM's want long term commitments from team members.
Never give up, but while you are waiting broaden your skill base with related training.
Keep the faith, If a window opens I will hand you a ladder. It will be up to you to prove yourself then.