If I understand this correctly you take your DP-N number and subtract any modifications from it to create a lower number, is that correct? I ask to correctly classify and rate my boat for future race events. I have looked at every spec for each Hobie 18 class and feel the inactive TheMightyHobie18 Formula is closest to what I sail. I would take the penalty for taller mast(SX) and non-standard main ( of equal or lesser size). And a separate penalty of .995 for my jib set-up(which isn't standard). If I'm calculating correctly ( 71.2(H18F) - .995(mast) - .995(main) - .995(jib) = 68.2 )

After several races with the boat I feel certain it will never sail to the 62.0 of the Tiger. I wish I could say differently but the F18s eat me for lunch. My boat is faster than the H18s even without the spin in most situations, which I am very pleased about.

If I'm wrong please tell me so, if I should calculate the numbers differently tell me. I'm trying to learn and be fair with myself and others. Thanks!