...and even more interesting, the fin shape!http://www.ebay.com.au/itm/windsurfer-mike-davis-designs-boom-fibreglass-CAIRNS-2400-x-530-/230734428373?pt=AU_Sport_Surfing&hash=item35b8d7f8d5#ht_500wt_1202
The fin was called a football fin if I can remember, horrible plastic injection moulded thing which I thought was great at the time{1990}I thought it went ok too!!!
I think footy fins were pretty much gone by 1990, everyone was starting to get pretty cluey and use pointers on race gear and wave fins like we have now - in fact some of those fins are still awesome for certain uses.
Dunno whatever possessed anyone in their right mind to make something like the footy fin though.
The coolest ones had strakers to (apparently) prevent spinout 
I remember in 1989 stairing at my new bright blue footy fin in awe at the space age design wondering where the guys in design found the creative wizadory to make such a master piece.... After several weeks and continual spinout issues I came to realise that the "wizadory" may have come from too much time hangin off a smokey pipey thingy.... 
