Factual error: There are two rentals cars driven by "Theresa" which have the same North Carolina license tag number, which is displayed on the front where required in Maine, the actual location of filming, but in North Carolina, license plates are not displayed on the front of the cars.
Continuity mistake: The state names on all the boats in the harbor have obviously been changed. The letters NC are a different size than the city name (New Harbor). This is because the movie was filmed in Maine and all the boats had the have temporary letters placed over the originals.
Continuity mistake: The scene where Garret and Teresa take the boat out for the early morning test sail. The wide shot cutaway as they are sailing out of the harbour has Teresa's left leg bent and laid flat against the boat. The immediate cut back to the two mid shot has Teresa with her left leg bent but lifted off the side of the boat. Pedantic but true.
Factual error: Throughout the movie we see several shots of the supposed NC coastline. None of NC's coastline contains giant pines on the beach or rocky cliffs at the water's edge nor does the coastline rise to over 12 ft above sea level for almost 30 miles inland (past the Outer Banks and the mainland sound shore).
Continuity mistake: In the letter in the bottle the girl's name, Katherine, is spelled with a K. The boat that is named after her is Catherine, spelled with a C.
Factual error: When Teresa is driving to meet Garrett for the first time, there is an aerial shot of a suspension bridge. There are no vehicular suspension bridges in North Carolina. That particular bridge is located in Maine.