I know excatly how do you feel...;-)
In November 2006, I was able to perform an exhaustive search in the 2002-2006 archives with the word "hypersonic". A number of 573 hits were found *. This is still true today :
The most interresting posts about which fins for HS105/HS125 and big sails (+10.x m2) are shown below :
1) fin for HS105, sail 10.5 and rider of 80 kg :
2) fin for HS125, sail 10.4 and rider weight 87 kg :
3) fin of 60 cm or more for HS105/125 :
4) best custom fins for HS105/125 :
However, these 7 links do not work anymore today (they did work in November 2006). I've tried numerous work-around, but without success so far, sorry for that. I might be wrong but I guess the old database has not been ported to the current one because of some sort of incompatibility between the 3 different forum systems that have been used since 2000.
Which HS do you have ? What's your weight ? Whats fins do you use with your HS ?
(*) : http://www.star-board-windsurfing.co...p?t=642&page=2