The ocean (or Great Lakes) is not a closed shop, Carpenters and Joiners can not demand membership before you dive.
I get the impression that you are trying to sea-lawyer your way to a rationale that in fact does some violence to the the intended definitions and objectives. If you'd describe exactly the activity that you're interested in, who will be doing it, their credentials and under whose auspices the work will be done (funding source and grants administration office) I might be able to be of more help.