This is the moment a CNN crew filmed a blue whale swimming directly under their boat. As part of Rolex's Perpetual Planet initiative, the conservationists on board are on a mission to advocate for ocean protection. cnn.com/calltoearth #CallToEarth #PerpetualPlanet | CNN

Blue whales can be found in all the world's oceans except the Arctic. These graceful giants typically swim at speeds around 5mph (~8kph), but can accelerate to more than 20 mph (~32kph) in short bursts. Blue whales generally undergo lengthy migrations between summer feeding grounds and winter calving grounds, but some evidence suggests that individuals remain in certain areas year-round. Video by Taichi Maruyama | Ocean Conservation Research - OCR

Drone footage captured this massive whale up close as the marine mammal made several passes under a boat to say "hi." | USA TODAY Video

Blue whale vocalizations are very low frequency sounds with some in the 15 Hz range. These tones characteristically travel long distances due to the high power, but also due to very long-wavelengths (over 300 feet for 15 Hz). This enables their songs to be heard thousands of miles from the source. We can assume that the projection distance is important (Nature can be extravagant, but she is never wasteful), but we can only speculate why they need to broadcast their songs across ocean basins. The