Also referred to as a tail slap, lobtailing is when a whale lifts its fluke (tail fin) out of the water and brings it down forcefully to slap the surface. The result is always a big splash and loud ‘wham!’
Lobtailing is a social behavior that calls attention to an individual. It might be used to impress a potential mate or intimidate a competitor.
The slap can be heard from great distances both above and below the water. It can lead to a call-and-response reaction from other whales. On the Silver Bank it is not unusual for one lobtailing whale to be “answered” by another, or to see a pair of whales lobtailing together.
Humpback whales will frequently lobtail repeatedly. They can throw their tail front to back, or back to front. Sometimes they’ll stop just long enough to take a breath before continuing on the other side.
Given that an adult humpback whale’s fluke can be up to 15′ (4.5m) across, it makes for a very impressive show!