Just another Moderator
Join Date: Sep 2005
Location: New Westminster, BC
Thanked 525 Times in 499 Posts
Rep Power: 10
Formula (approx distance) d = 1.2246* SQRT(h); d in miles with h in feet.
Using this, you get 3.87 miles distant at a 10 foot height; 5.47 miles at 20 feet. 50 feet up gets you out to 8.659 miles. This is, ostensibly, distance to the horizon so taller objects 'over' the horizon could still be visible. Light refraction also affects the truly visible range... might not affect radar.
This method does not account for the curvature of the earth. Consider how "far" you could(n't) see sitting in a life raft.....
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Last edited by Faster; 01-13-2011 at 07:22 PM.