Bonnie -- Poster asked the same question in the MA Forum, but specified Rockport, ME....
Best response I could find was: Concord Coach Lines (good, reliable, clean-coach service) lists departures from Camden/Rockport at 8:30AM and 12;30PM, arriving at South Station, Boston at 1:25PM and 5:25PM respectively. From South Station, it's a one-change subway ride to Fenway...
But goiing to a game and back to Rockport afterwards would require an overnight because northbound service to Camden/Rockport leaves Boston at 12:01PM and 5:25PM, arriving in Camden/Rockport at 5:25PM and 9:45PM respectively. If you wanted to do that, an overnight in Portland, ME would likely be less expensive than staying in Boston. Concord Coach (or Amtrak Downeaster) both offer more frequent Boston-Portland service and you could pick up Concord to Camden/Rockport as it came through Portland the next day. (See Concord Coash website for full schedule, locations of stops, etc.).
Thank you. Guess we won't be going to Fenway unless we drive.
Well, you could drive partway, then take public transportation. Depending on the time of day and our timeline for return, we have used Concord Coach out of Portland, C&J Trailways out of Portsmouth, the Amtrak Downeaster (we get on in Saco, but you would probably choose Portland) or we drive to Revere, MA and pick up the T. With that option, we take the Blue Line from Wonderland, then swap to the Green Line at Gov't Center. Any train except an E train will take you to Kenmore.
Agree with CB,,,, don't give up yet... Drive Rockport to Portland, Concord Coach from Portland to South Station (or Amtrak Downeaster to North Sttation), and subway to ballpark.... After the game, subway to South (or North) Station, bus (or train) to Portland, drive yourself back to Rockport....
Portland-Boston and Boston-Portland busses run almost hourly except for wee hours of the morning...; parkng in Portland is far less expensive than if you drive into Boston; and its definitely more enjoyable to let someone (anyone) else drive in Boson traffic.
I'd check game times for dates you might want to go; match them with Concord or Downeaster schedules (both easily Googled), and go-for-it. Afternoon game will likely give you the most flexibility, but a night game could work so long as you make the last bus/train of the night back to Portland.
Added tip: save yourself a little time from Rockport to Portland... use ME Rt 90 to ME Rt 17 to I-95 in Augusta, then i-95 and I-295 to Portland (super easy access from I-295 to Portland Transportation Center and overall easier driving than taking US Rt 1).
Thank you all for the suggestions.