Actually her answer was pretty good.
A lumen equals one foot candle of illumination over one square foot. If you know the lumens and the angle, you can figure the rest. And how much illumination you then have in any given square foot depends on the distance from the light to the subject.
That tells me a lot more than "three Luxeon K2 LEDs" as to make any useful sense of that I need to see the specs for those LEDs and you didn't post them.
The only thing her response lacked was the color temp of the light and that can be assumed to be pretty much in the white to slightly bluish white range common to most LED lights in that class.
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A "lux" is a lumen per square meter (so the name of the light implies 1000 lumens per square meter.) A circle with a diameter of 1.13 meters would have an area of 1 square meters. With a 12 degree angle, the beam will cover 1 square meter at a distance of about 5.3 meters, or about 17.3 feet. So if the name is correct, you would expect 1000 lumens of illumination over an area of 1 square meter at a distance of about 17.3 feet. Since it puts out 975 lumens, you get 975 lumens of illumination in a 1 meter circle at about 17.3 ft (minus what ever got absorbed by the water).
What does that mean? A cloudy day has an illuminance of about 2000 to 10,000 lux. A dull heavy overcast day has an illuminance of 100 to 2000 lux.
That sounds bad until you consider that the average office has about 200-300 lux and the average living room has 50-200 lux.
Comparing to other lights is fine, but you need to be able to quantify it to something that is actually meaningful.
Personally, I use a 700 LED when cave diving and it is plenty of light in most caves. In some of the bigger and darker walled systems (some parts of Manatee, etc) I find I could use a little more light and a little more penetration.