Quote
The Viper is designed to be 125kg with a crew weight of 120 – 140 kg. The hull buoyancy and shape is designed around this.

Interesting weight zone, it seems to be in no mans land, most blokes I know are with sailing trim around the 75 -85 kilos which then means that only your son or daughter is really optimum crew. With the extra bouyancy and modern hull design I guess its not really going to matter but I think as a single hander it maybe a bit porky in the lighter stuff, I guess one shouldn't make assumptions just yet