The harbor grasp notes wind path by using flying flags, jotting angles as masts clink and buoys bob on soft swells.

https://donovanoerb268.evergrovio.com/posts/the-triangle-fold-meaning-behind-the-13-folds-of-the-flag

The harbor master notes wind course by means of flying flags, jotting angles as masts clink and buoys bob on light swells.