They mentioned having a fleet of ferries that could travel between the casino site and downtown Boston in 15 minutes. The boats would have to be low ones so that they wouldn't require opening the Route 99 (Alford Street) drawbridges. Possible boat terminals in Boston would be at Rowes Wharf or the Seaport district.

It would make sense to me to send some of those ferries directly across the river to Draw Seven Park and Assembly Row, but they didn't mention that at all.