Public transportation is your problem - it is really limited on LI to RR stations ( or limited bus routes which take forever to get around.) Why not rent a car for a day? Compared to RR tickets it may not be that much more and would open up a lot more options. Also, the walk from the Port Jeff RR station is downhill to the harbor, the return trip is up hill and I doubt most people could do it in 15 minutes - what will you be carrying?
Most probably I'll be carrying a kata backpack with 35mm and MF kits inside, and perhaps a manfrotto tripod, depending on the difficulty of the trek.
Uphills don't bother me too much. I'm originally from Tennessee, and I've done more than my fair share of hiking in the mountains there. It would actually be nice to see a little more elevation change. I'm always up for a challenge