I just joined inland boatmen union

I just signed up for the union, the receptionist was really helpful but should I keep showing up for a few hours after my day job to get a contract or just keep calling once a week to stay on the list? Is it just a waiting game. Are there very many job postings or is it once in a blue moon do you get something? Is it a good foot in the door to get seatime and get other hitches afterwards or will I get one contract for a bit and be done