70 kg - 95 kg is competitive range with 75-85 being optimal I think. But the spinnaker handling requires so much skill that the onus of competitiveness is really very much shifted to skill rather then skipper weight. Getting that kite up and drawing or getting is down and carving a tight turn through the gate are just difficult things to execute perfectly. If you don't then you easily throw away 10's of meters or seconds. Going wide through the gate is especially hurtful.

Wouter