Clarity is a key issue. Naturally, the clearer the water the further you see. The CatchCam can usually see about 5 feet in near dark conditions and even greater distances in clearer water. This is a good question. Green penetrates deepest in the water column and red, theoretically, is filtered out of the spectrum within the top 15 to 20 feet.
Lights are legal in Canada and every state.
However, there is a restriction for Minnesota residents. The Minnesota DNR specifically states that the use of lights in the taking of fish while spearing, is strictly prohibited. Coating a lens with an anti-reflective substance will increase the transmittance of the image making it brighter and will reduce the glare and reflection of light on the lens. This will allow you to see the image better than displays not using an AR coating. Dust and fingerprints are the most common contaminants and can usually be removed with a dust free lens tissue and lens cleaning solution.