Forestay Sag calculation

HI Group, I did some Google type research and a little math trying to come up with a formula for forestay sag. I found a few sources that agreed on certain aspects of this and some that seemed to have some obvious 2x errors but agreed other than that and ultimately formed an opinion on how to calculate forestay sag. I know of no better way to figure out if something is right than to put it out there and watch people pick at it so... Sag = .12 * SA * V^2 / T Sag = Forestay Sag in inches SA = Sail Area in square feet V^2 = wind speed in knots squared T = forestay tension in pounds For example, 244 sq ft sail, 25 kt wind, 2800 pounds of tension sag = .12 * 244 * 625 / 2800 = 6.5 inches Anyone think this is either right or wrong? If anyone gets into this, I would measure forestay tension by measuring the stretch of the forestay from slack to tight and applying this formula: Stretch in percent per 1000 pounds = 6.4 / (1000 * FA) Where FA is the forestay area in square inches So, for 1/4 inch wire the stretch is 6.4 / (3.14 * .125 ^ 2 * 1000) = 0.13 percent per 1000 pounds and for a 40 foot headstay that would be 5/8 inches per 1000 pounds. I am open to anyone pointing out that this is all wet as well. Speaking of all wet, off to the boat to inspect my leaks. I am down to only two plus one small one I don't count. Allen