New in 2016. Parking for maybe 8 cars in dirt lot. Elaborate launch point. 200-250ft walk from lot down to dock, combination of stone steps and ramps, generally steep and a bit awkward to carry on - there is a dirt path already worn around the top section of boardwalk and steps which is a less awkward carry. There's another set of stone steps without a way around so wheels aren't overly helpful. The last ramp down to the floating dock is very steep unless the water is high. There is a cradle on the dock with rollers and handrails so you can get in your boat dry and launch, and also exit that way. It reminded me of boarding a log flume ride at an amusement park. (So all very nice and new and pretty, but felt designed by someone who has never carried/launched any sort of PWC?)
The Bill Ashe Visitor Center itself is just a little up the road at 80 Hospital Rd. I believe it is technically in Devens but my GPS still considers it Shirley. I know there are bathrooms but I don't know if they are always open or have season/hours.