The interaction between these two whale species described here is not an isolated case. Although Orcas are the greatest natural threat to Sperm Whales (apart from humans of course), they have also been observed being chased by Pilot Whales.
Excursions and field biology trips are often the order of the day during a biology degree. I believe that it is the time away from the lecture hall that is most vividly remembered and often groundbreaking.
One of the Killer Whales seemed particularly curious, swimming under the boat, leaning a little to the side and looking us straight in the eye. This moment burned itself into my memory so strongly and it simply would not leave me.