NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Glowing Sea Surface
From: George Huxtable
Date: 2003 Nov 10, 10:14 +0000
From: George Huxtable
Date: 2003 Nov 10, 10:14 +0000
Trevor Kenchington, in an interesting posting, said- >At sea in bad weather, at night, I have often noticed that the surface >of the water seems surprisingly bright. I have put that down to streaks >of foam catching the light from my ship's masthead lights and reflecting >it back. and added more detail about his observations on the night of a hurricane. My own observations may not relate closely to what Trevor saw, being in a different part of the world, at a different season, and under very different conditions. Nevertheless, here goes. ============== I got a fright, one black but pleasant summer night, out in the middle of the English Channel. No wind, so I had lit up my little diesel. Opening up the engine hatch, to give the stern-tube its regular gob of grease, I saw a brilliant blue flash that lit up the engine compartment: then another and another. This looked just like a big electrical problem, until I tracked it down to the transparent plastic pipe which connects the cooling-water inlet seacock to the pump on the engine. I then attributed the flashes to some form of marine life that was protesting against the indignity of being sucked through that pipe by giving off a flash of blue light. What it thought about its subsequent treatment, whirled around the rubber vanes of the pump, passed around the engine jacket, mixed with hot exhaust gas and spat out at the stern, I can only imagine. The blue display got more intense, showing up next as a bright blue glow from around the slipstream of the propellor, displaying the flow pattern just like a diagram in a hydrodynamics text book, only far more beautifully. I took it that the same organisms were responding to the pressure-disturbance from the propellor blades. Also, the puny bow-wave that my boat raises under engine was painted a glowing blue, and I could see, on the water surface well away from the boat, wide arcs of a faint blue light. Altogether, it was a magical night, one that my wife and I will always remember. We have seen similar effects since that night, but never anywhere near so intense. I expect that it's a phenomenon well-known to marine biology. In that instance, I'm sure that it related to individual glowing organisms, not to a general glow from the sea surface (although that's what it might have looked like from a distance). That's it (for what it's worth). I know it doesn't answer Trevor's questions. George. ================================================================ contact George Huxtable by email at george@huxtable.u-net.com, by phone at 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ================================================================