What time of day is most suited for underwater photography / filming ?
When do I get the best light?
In contrast to film and photography on dry land, where the best light is generally found early in the morning, or late in the afternoon, noon offers the best light for under water footage.
The reason for this can be found in the light filter properties of water. After only 1 m (3 feet) the ray of light passing through water has already noticeably lost some of is red colour spectrum. For that reason we tend to use that time of day for our footage in which the light has the shortest distance to travel through the water on its way to our lens.
That is the time, when the sun is directly above and generally speaking
between 11:00 a.m. and 2:00 p.m.
(and if possible at low tide...)