Solar on the mast, just saw it mentioned somewhere else then I found this thread by coincidence.
When considering the angle of incidence of the sun, it is normally for static installations (land based), with surrounding terrain of various sorts and variations. At sea, besides being on a moving platform, one should consider that - especially high up in the mast of a sail boat
- there is a lot of reflection coming from the sea. This obviously depends on waves, visibility, cloud cover and such. If you think it doesn't work, think how fast you tan at sea:
In other words:
Morning and evening, you get an optimum angle for that initial boost to get things going and a top-up in the evening before sunset. But all day, a huge mirror around you provides plenty of reflected light.
I don't know how significant it is, especially not for those frequencies of light that are reflected.
If someone out at sea has a loose solar panel they can move about, the sun high enough in the sky, try and move it in different directions to see how the yield varies.