I would take almost for granted, that he has used 2003 formula 147. Only 2003 and 2004 boards had the IQ sign so close to the back edge of the board, but the 2004 board had wider white strap just behind the latter screw of the fin. I would never tell, that he would use so old board for speed contest, but obviously Nick considered it the best choice. I myself still sail on 2001 175 Formula wood edition and love the board. What's interesting this board of mine is lighter ( 8,6 kg vs 9.x) that nowadays 20012 and 2013 Fomulas.
Bart from Poland