I don't think Scub Island offers any discounts. Even with me showing them their TTOL advertisement(Pre Irma), Scrub would still not honor their discount. After much gashing of teeth, I finally received it by email correspondence.

With that said, we really enjoyed their pool/ pool bar and outside restaurant. Their ferry generally runs late in evening(9Pm?-11Pm?) so would not be surprised if it does not run after midnight on FMP nights