I can't take credit for these two photos, they were taken by son Steve, but I wanted to share them with you all.
He also works on tugboats running between the US Pacific Northwest to Alaska. He took these shots at 0055 this morning (for you landlubbers, that's 1255 AM) Alaska Time. There is still a little daylight left at that hour during the summer months in Alaska. The view is looking aft over the stern of the tug. You can see the tow wire leading aft into the water back to the barge he is towing. The water is illuminated by "Bioluminescent Plankton" which is being stimulated by the tugs propellers.
The bioluminescence results from a light-producing chemical reaction also called chemiluminescence. Certain types of chemicals when mixed together produce energy which ‘excites’ other particles on vibration and generate light which causes the glow. The group of chemicals involved to make plankton glow are broadly termed luciferins and the light is produced by a series of oxidation reactions set off by a catalyst called luciferase. The bioluminescence in plankton is very high in several forms of Plankton and is a form of cold light or luminescence.
Steve apologizes for the noise in the photos, but low light and a moving boat make it tough.
Taken in Lynn Canal, between Haines and Juneau, Alaska.