After the success of the first attempt, for the second prototype I wanted to address the main problem with the first board, namely that of the weight. My solution to this was to vacuum press a lovely strip of zebrano wood veneer that I'd managed to procure, to the deck. The result of this experiment could only be described as an unmitigated disaster! Importantly though the lesson I've managed to learn from this is that a cheap ebay vaccum bag (used for storing clothes conveniently in the attic for the winter) and an ill-fitting home vacuum cleaner doesn't make for effective vacuum pressing. Coupled with that a rippled sheet of veneer and a wood that splintered easily meant the end result was horrendous.
A great deal of work and many sand bags later I'd managed to repair the board to an acceptable standard enabling me to finish shaping and laminating. The end result certainly succeeded in my main aim though, it was certainly a good deal lighter than my first board, just a shame I have no plans of using wood veneer again any time soon!
One other positive result of this model was with the balsa keel fins. Rather than simply cutting the fins from a sheet of 5mm balsa and fibreglassing, which took a good many layers of fibreglass to achieve the necessary strength, I opted to make some balsa ply from three sheets of 2.5mm balsa. A great deal stronger meaning a lot less fibreglass.