Amtrak operates a bus from Boston to Seabrook every 2 hours, and the journey takes 30 min. Coach Company also services this route every 3 hours. Alternatively, MBTA operates a train from Boston to Seabrook hourly. Tickets cost $6 - $11 and the journey takes 1 h 3 min.
From Boston Sth, MA Amtrak Thruway to Newburyport, MA then taxi to Seabrook. 38 min $63. From North Station train to Newburyport then taxi to Seabrook. 1 h 15 min $69. From Boston taxi to Seabrook. 48 min $312. From Boston drive to Seabrook. 48 min $5.