Visible crew/equipment: While Quint tells of his experience with the U.S.S. Indianapolis, in the close-ups of Brody a crew member's arm with a watch is clearly visible moving in the reflection on the window, just behind Brody, particularly when Quint says, "Anyway, we delivered the bomb." (01:32:55)
Visible crew/equipment: As Hooper says the shark is "back for his noon feeding", you can see the camera and lighting reflected on Brody's glasses.
Visible crew/equipment: When Quint is doing his speech at the town meeting the camera slowly moves towards him. When the camera passes the man in the grey suit you can see a moving shadow near Quint. Everyone in the room is stationary in this scene apart from the cameraman and film crew. (00:20:55)
Answer: Possibly a scar from having his appendix removed, I've been told.
The appendix shot is Brody - he is feeling inferior as the other two share tales of the sea and the only scar he has is from his appendix being removed.