The Canada Goose mysteries

Over recent years the number of unusual summer records of Canada goose have been increasing. Today was no exception.
11:50 (30 minutes after high water) - These 14 flew low from the east, first seen between Pott's corner and Ocean Edge salt marsh. They settled on sea c600m out from Red Nab (MD).

This graph may explain the mystery.

Thanks to Pete Crooks for the following observations of low tide skeer:
Great-crested grebe 10
Red-breasted merganser 1
Bar-tailed godwit 30
Canada goose 10 north