That distance takes in a lot of territory so I'll just focus my answer on when you cross the NH / Maine border. In Portsmouth NH - Strawberry Bank is near the water and nice collection of shops/restaurants. When you cross the bridge into Maine (route 1) and enter Kittery bear right on to route 103 and go along the coast. DW and I have gotten lobster at Captain Simeon's restaurant while looking out the window and seeing the fishermen pull up lobster traps (can't get any fresher than that
). A few old forts around the route are great to stop at. At York Harbor (pronounced "Yark Haabaa"
) you meet up with I95 (fastest), Route 1 goes thru towns or my personal favorite Route 1A (then 9) which huggs the coastline along which you will see the famous lighthouses (hooks back up with Route 1 off and on). Its all about the time you have to "smell the roses."
FYI- The shore area in NH (birthplace and hundreds of relatives there) is traffic jam city in the summer. Would avoid JMO.
Arcadia NP is great also if you have the time its just North across the bay from Rockland.
Lived in NJ for five years and returned from Disneyworld via Norfolk VA crossed the Chesapeake Bay (Route 13 - bridge than tunnel) (make sure you stop at mid point parking area and display) then into Delaware and at Lewes took ferry to Cape May NJ (crossing the Delaware Bay). Very unique route and the DW, two sons and I loved it. We used rented car - so check if RV (propane) can use tunnel.