Back in the mid 1990's I was on a 88 foot double masted schooner called the Ocean Star sailing out of Key West. I was there as part of a seminar at sea training course learning about nautical things like celestial navigation, radar plotting, etc... We anchored in the Dry Tortugas and then headed south where the plan was to sail close enough to Cuba to be able to see the mountain peaks such as they were while working using our sun sights for navigation checks. The first night out while sailing nicely along at eight knots we started to notice glowing objects in the water all around the boat as we sailed. They were of various sizes though most were the size and shape like a football. None of those on board including the Captain and crew had ever seen such glowing objects before. Many of us were familiar with the bio luminescence phenomena we had seen in harbors and beaches. But, these objects were much bigger.
We surmised that perhaps we were sailing through an immense shoal of squid. Their oblong bodies being the source of the illumination we were seeing. But, we were not sure. The mystery of exactly what we saw that night has always intrigued me from time to time over the years.
Then this winter I started reading The Long Way by Bernard Moitessier. I discovered the answer to the mystery I and the others had seen on the schooner over twenty years ago. My AHA moment came when I read this passages in Moitessier's book:
"Here and there, large flashes the size of a soccer ball appear in the sea, shining like giant glow warms. I have often seen them in the trades, and kept them in sight for sometimes thirty seconds before they went out. At first, I took them for the eyes of strange animals risen from the depths. I had even harpooned them, from the deck of my second Marie-Thérèse, both disappointed and relieved not to haul up a giant squid gnashing its beak at the end of my harpoon."
It seems he too had also surmised that they could be groups of large squid emitting the glow. But, he explained a little later on what they really were:
"The globes of fire that I saw in the waves earlier can be seen more than a hundred yards away now that the fog has lifted. They are plankton colonies, not the eyes of monster squids; I read the explanation somewhere. But I will probably never know why they shine so brightly, only to suddenly go out for no apparent reason. I would like Joshua to surf into one: at that speed, it would make fabulous fireworks in the staysail."
So the mystery that haunted my memory for all those years is solved thanks to Mr. Moitessier.