There is a great book by William Warner called "beautiful swimmers"
and it explains all of your questions and more. Once you pick it up
you will not be able to put it down. This is a pulitzer prize winning
book from 1976.
READ THIS BOOK!!!. I have read it 3 times during the winter months and I learn something new every time. Also, good waterman books like Barcat Skipper and Smith Island: A Memoir of an Island out of time are both excellent books that help you relate to the commercial crabbers and their histories.
Welcome to the board and look forward to hearing our reports.