I’ve only recognized Dike this one time on July 24, 2012 in Handtrollers Cove off the northwest end of Shelter Island. The very small patches of white at the far end of the flukes near the trailing edge look like someone lightly sprayed paint on this otherwise solid black tail. The central notch is a broad “U” and the right fluke is strongly serrated with two prominent ridges next to a prominent broad scallop near the middle of the fluke.
The NOAA tail site notes this whale is “Regularly seen in Glacier Bay National Park. Known male. Nicknamed ‘Dike’ by Chuck Jurasz” and was first seen in August of 2004.