After doing a little research and asking experts at the aquarium in the Baltic city of Stralsund about the seldom-sighted creature, the sailor realized how little it had been caught on camera and so uploaded his video onto YouTube.
Snapped in the Fehmarnbelt between Germany and Denmark, the video shows a group of porpoises - including the elusive white one - swimming alongside a yacht.
The WDC believe that the footage, which was taken off the Baltic coast last spring, is the first time that the white porpoise has been filmed in German waters, the group announced.
Entirely white dolphins and whales are thought to be extremely rare and over the past 100 years white porpoises have been caught just 14 times on film worldwide. Normally the animals only have a pale belly, while the rest of them is relatively dark.
But whether or not the marine mammal was a true albino will never be confirmed, the WDC added.