Timing is everything.http://www.youtube.com/watch?v=PDoe5JoUYAw&feature=player_embedded
That video was misplaced on google earth. It's from a beach north in Nicaragua. Same diff., many beaches along the coast have the same turtles.
This shot is from my trip flying over your beach. This is the north end of Papagayo, you might find a trip up that river.