Originally Posted by
bigjimg
I use a simple rule. My chain is 8mm @ 7m long and warp is 12mm attached to a Lewmar 6Kg plough. I have 10m increments marked on the warp with spay ink. If for instance I am in 15m of water I will move off the mark a known distance, in this case .025 of a Nm or 46 meters.
So 15m squared =225 and 46 meters squared = 2116. 225 + 2116 = 2341. Square root of 2341 = 48.383 meters of rope +/- depending on conditions. Using these sums and with my setup I have never dragged anchor. Once you get to know rate of drift you should be able to set your anchor positively by backing it in. Jim.