Try this for part of the way:
From Winter Island Campground in Salem MA., to South Station in Boston.
Take Fort Ave. .7 miles
Turn LEFT onto Essex St. and go .4 miles
Turn LEFT onto Rt. 1A, follow .3 to 1A / 114
Turn LEFT onto 114 and follow 3 miles to 129/Ocean Ave
From 114 & 129 take 129 / Atlantic Ave southwest 2.6 miles to Puritan Rd.
Turn LEFT onto Puritan Rd., skipping the park and preschool traffic in favor of a longer stretch of beach.
Follow 129/ Humphrey St. WEST another .7 miles and bear left onto Lynn Shore Drive.
Follow Lynn Shore Dr. 1 mile and you’ll come to a rotary (check out Nahant Rd. to loop to Little Nahant for a scenic ride, but a detour from getting to Boston).
Leave rotary headed Northeast on the Lynnway, witch will become Rt. 1A. This stretch is terrible but can’t be avoided completely.
Take a LEFT onto Marine Blvd. which will take a right before becoming Riley Way. Riley Way and Riley Way Ext. do not connect.
The Riley Way ext. will take a sharp Right and become Hanson St.
You can either take Hanson back to 1A & go LEFT or continue on straight on the path along the shore which will hug the water, curve right and meet 1A at the General Edwards Bridge. Take the path, 1a is nasty.
Once over the bridge, take immed. LEFT onto Rice Ave. which will hug the beach, and keep you of 1A.
At the end of Rice Ave. , take a Right onto Harrington and an immed. LEFT to get back to Revere Beach Rd.
Follow Revere Beach Blvd. South 2.7 Miles along the beach to the end, at Eliot Circle.
Food stops across from beach, toilets / water at bath houses.
Stay Straight / LEFT onto RT 145 / Winthrop Pkwy for .2 miles
Turn RIGHT onto Jones Rd. for .2
Stay straight onto Atlantic for 300’
Take 140 degree LEFT onto Unity follow 300’
To Beachmont “T” Station. Elevator to get onto the platform
At this point ,a decision needs to be made to on how to cross the river into Boston.
The “T” (blue line) to the Aquarium stop, which is not far from the South Station.
There may be a commuter train to Prov. From East Prov. take the East BAy bike path to Bristol, either ride over the Mt. Hope Bridge (scary) or Ripta bus over the bridge