I’ve seen the National park service hiring every now and then on usajobs.gov, although almost all their stuff is really small tonnage. Last year I saw a job running a 100 or so foot vessel from the keys out to the dry tortugas. May not pay much but lots of scuba diving and fishing I’m sure. Back in my home state of Michigan I’ve seen them looking for crew for the Ranger 3 and occasionally a tugboat captain for a 45ft tug pushing a small oil barge to Isle Royale. Doesn’t pay much but it’s beautiful up there in the summer and you’re probably laid off for the winters to do what ever you want.