Seabrook is represented as two industry sidings plus a small neighborhood around Railroad Avenue with the railroad bridge plus the start of the salt marshes looking out at the cottages at Seabrook Beach.
Here is the closer look at the track plan section for Seabrook from XTrackCad:
The track passes from staging in front of the backdrop that hides the helix.
We immediately come to the first Seabrook siding at Isabel's Coal and Ice.
The current building at Isabelle siding is just a stand-in until I find or build an appropriate building for Isabelle Ice and Coal.
We then continue north along the tracks to Walton Road, where we see a small neighborhood and the railroad bridge over the road.
As we continue north, we come to the second of the two Seabrook sidings. Here we will find a couple small industries as well as the team track.
Area is just starting to take shape with a couple stand-in buildings.
Finally, at the northernmost end of Seabrook, we have the salt marsh and a view of the cottages at Seabrook Beach. For those not familiar with the area, the cottages are on both sides of route 1A and tend to be arranged several cottages deep between the beach and the road as well as between the road and the salt marsh.
From there, it is northward through the woods heading to Hampton Falls.