Acknowledging Capta's astute word of caution, September is a terrific month for cruising the waters of RI & MA -- so long as Mother Nature doesn't send any unpleasantness barreling up the eastern seaboard.
We made our maiden voyage to Block in August of 2011; I hope we get back sooner rather than later. The harbor master directed us to the showers at the beach that Tempest describes. Pretty primative -- what one would expect for showers at a public beach -- but got the job done. Tokens were something like $3 each. Didn't know about the Oar showers; wonder if they'd have been better, worse, or the same. Will have to check 'em out next time.
Ate dinner al fresco at Hotel Manisses. I confess I don't remember it being as fancy or expensive as their website
makes it look, but I guess perhaps it was. The food was spectactular though, as was the setting. Even more importantly though, avail yourself of whatever treats Aldo's brings around by boat in the morning. Just listen for the sounds of "Andiamo!" echoing through Great Salt Pond and wave 'em over!
Have a terrific week. . .