I was talking with the Coast Guard today. There is going to be a new ID card required for anyone working on a fishing boat, transporter, 6-pack....basically everyone on the ocean except private fishermen. There is no handout or information on the internet that can be printed yet. They are working on it.
Either way, you had better check with the Coast Guard before heading out this spring. This new card is a requirement of the TSA in conjunction with other agencies.