i reckon dropping the board size sounds good and will get more in, just get the judges to judge like a longboard comp, we have guys prone surfing their big sups in the mal division at our local Boardrider club comps
Judging Criteria for Longboard
The Surfer must perform controlled manoeuvres in the critical section of the wave utilizing the ENTIRE board and wave using traditional longboard surfing. The Surfer who performs this to the highest degree of difficulty with the most style, flow and grace will receive the highest score for a Ride.Further to that above, the following are key elements for judges to consider:• Nose riding and rail surfing
• Critical section of wave
• Variety
• Speed and power
• Commitment
• Control
• Foot work