We're not the only mammals to notice the oil tanker entering the Gulf of Amvrakikos.
Some of the dolphins we're watching notice it too, and several of them change course to intercept it. We follow alongside, and see the animals bow-surfing and spectacularly leaping 5 meters out of the water. Speeding alongside the tanker in our inflatable, it feels more like we're Greenpeace activists than dolphin researchers.
It was the beginning of July, and as I chased dolphins in this part of the Ionian Sea in Greece's northwestern province of Epirus, which borders Albania, cinemas across Japan had finally begun showing "The Cove," the Academy Award- winning U.S. documentary about dolphin hunting in Taiji, Wakayama Prefecture.