The humpback whale’s pectoral fins can be up to 15′ long, proportionally the longest of all whales. A humpback whale can lie on the surface of the water and slap the water with its pectoral fin.
On our second whale watching cruise in Maui, we saw a whale slap the water with its pectoral fin. In the slideshow below, there are two whales, one behind the other, with the island of Lanai in the background. The sequence starts with the back whale raising its pectoral fin and ends with a splash. The elapsed time is almost a second.
The dorsal fin of the front whale is visible. The whale in back is lying on the surface behind the first whale. The whale in back raises its pectoral fin and slaps the water behind it, away from the front whale. Perhaps the front whale is a female, and the back whale is a male.
At the beginning of the sequence, the front whale is lying flat on the surface. By the end, the whale’s back is bent and the dorsal fin is raised — the whale is getting ready to dive. Here’s the tail with water streaming off, 3 seconds later.
There are some white spots at the back edge of the tail. As seen in this crop from the photo above, the white spots are barnacles, all clustered at the tip of the tail.
These whales were near our boat — the photos were taken at 100 mm, the shortest focal length on the 100-400 mm lens. An interesting feature of the Canon 100-400 mm lens is the push-pull action to change the focal length. Lenses usually have a ring that you twist. After you get accustomed to the push-pull, it’s very fast for zooming, especially useful when photographing wildlife where you make rapid adjustments or lose the shot.