I, for the record, did not advise anyone to use a filter. I simply addressed the commonly stated falsehood that electronic white balance obviates the need for and usefulness of filters. It just isn't so.
If an ambient light shot taken at 70 feet without the use of filters can produce more color detail than the shot I provided I'd sure like to see it. Otherwise, I hope everyone understands that filters and white balance are absolutely not interchangable.
To answer the example I provided, red light is attenuated at least four stops by 30 feet. Digicams like the 5060 offer 6-7 stops of useful dynamic range. At 30 feet, therefore, the red channel of an image can, at best, have only 2-3 stops of "red light" detail unless you use a filter. That's 4-8 discreet values only. Such an image would be severely posterized in red and anyone can easily demonstrate this for themselves. Unfortunately, the problem gets worse. Violet light generates a response in the red channel and violet is attenuated at only half the rate of red. Without a filter, violet detail will overwhelm red detail. That's why filters generate MORE accurate color, not less. Once you get into a tristimulus model you're screwed.
I would expect that, at 70 feet, no digicam will successfully white balance to a gray card without a filter. Haven't tried it myself, but I have tried it with one of the best camcorders ever for this purpose and it can't go much beyond 30 feet (it goes to 70 feet with a filter). At 70 feet, very little red light exists but violet does and in quantities that vary with water clarity. I would expect there to be a 6-7 stop difference between red and green in good conditions. That's a huge difference to ask any current camera to overcome.