As it was said, they are in there sometimes. My first striper ever was caught by casting a Storm rubber shad at the Braga bridge pilings in early May. I don't know your situation, but if the boat is being trailered, the best ramp is in Somerset. They charge a few bucks during the summer. Othewise there is a tackle shop under rte. 24 in Tiverton with a nice ramp. Also a small fee to launch. Good fishing to be had in the Tiverton area at the "Old Stone Bridge" and at the old train bridge near the tackle shop. Quite a rip when the tide is changing. Again, early season spots. After June 1st, it just slows down to nil. There is a tackle shop in Berkley, on Padelford street. A guy runs it out of his garage. Great guy. Steep prices. Always has stories about the fish that was weighed in 10 minutes before you got there. He swears every year is the best he's ever seen. Says there are fish to be caught in the Sakonnet river. I have yet to find any. He'll happily sell you whatever expensive gear is catching them though.
Wal Mart in Swansea, at the Swansea mall usually has a nice chart of Narragansett bay at the sporting goods desk. It is marked up with fishing "Hot Spots", which incidentally are at the wrecks, shallow areas and submerged structure, which is really what you want to find.