Our experience has been that “T” foils do all and more than we expected from them. They dramatically reduce the pitch of a hull (which after all nose dive is just pitch to the extreme) and they do all this without any noticeable drag or detriment in any other area of performance. The also make the rudders more efficient by reducing the effect of “tip vortex” (which effectively reduces the usable area of the rudders). If you want to know the effect of T foils on monohulls talk to the sailers in the International 14’s, their whole class has been revolutionised since the added T foils to their class.