Shark Cam, Monterey Bay

The aquarium's Open Sea exhibit holds over a million gallons, and its live cam is the closest most of us will get to hanging motionless in blue water. Hammerheads and soupfin sharks patrol through clouds of sardines that move like weather.

The sardine bait ball is the hypnotic centrepiece: thousands of fish shifting as one organism, parting around the sharks and reforming. Mahi-mahi, tuna and sea turtles make cameos.

Watch during California daytime for the best light in the tank, and don't skip the quiet hours: the slow patrol of a shark through empty blue at closing time is meditative in a way few live feeds match.