The current schedule for CA to RT ferries is 9:00am, 2:00pm, 4:00pm and 530pm. I would expect the June to be about the same, maybe the 2:00 or 4:00 goes away. It also depends on the day of week you are arriving. I believe there is also a late ferry out of Red Hook by Aquatic. The best way to confirm is going to each of the ferry web sites: Smiths, Road Town Fast Ferry, Native Sun and Speedy's. With your 442 arrival at STT you may be hard pressed to make the 530 ferry. Bags usually come out pretty quickly, like 10 minutes and the taxi to the ferry terminal is 10 minutes. There are other options if the ferry doesn't work for you. Hope that helps a little.