According to the plans which came with my 1972 Rasmus 35, the height of the mast above waterline is 13.5 M plus the height of any antena fixed to it. This tallies with the copy of the Rasmus 35 specifications which I downloaded from the following url:www.classic-hrs.com/Hallberg/boatphotos/BillSailBoat1.jpgHope this helpsJeremy PJ