Ric Says
• Glickman's landing gear debris field at about 61 meters (200 feet). Still plenty of ambient light and marine growth at that depth.
I think that is an overly optimistic assessment.
From Wikipedia
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With increasing depth underwater, sunlight is absorbed, and the amount of visible light diminishes. Because absorption is greater for long wavelengths (red end of the visible spectrum) than for short wavelengths (blue end of the visible spectrum), the colour spectrum is rapidly altered with increasing depth. White objects at the surface appear bluish underwater, and red objects appear dark, even black. Although light penetration will be less if water is turbid, in the very clear water of the open ocean less than 25% of the surface light reaches a depth of 10 m (33 feet). At 100 m (330 ft) the light present from the sun is normally about 0.5% of that at the surface.
The euphotic depth is the depth at which light intensity falls to 1% of the value at the surface. This depth is dependent upon water clarity, being only a few metres underwater in a turbid estuary, but may reach up to 200 metres in the open ocean. At the euphotic depth, plants (such as phytoplankton) have no net energy gain from photosynthesis and thus cannot grow.
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I also found this description that matches pretty well
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At 300 ft (90 m), most of even the blue light (the most penetrating) has been absorbed, while below 650 ft (200 m), the only light comes from bioluminescent organisms, which produce their own light.
http://oceana.org/es/explore/marine-science/light-and-sound>>>>>>
I would not expect much marine growth on an object that landed at 200 ft given the minimal amount of light down there. I haven't been able to find a formula, but clearly the light attenuates at an exponential rate.
Andrew