In light wind and flat water, you can get amazing performance out of a relatively short 140cm board and 18 to 20 inches(45-50cm) wide.
I made a 5ft by 20in plywood with slightly offset to heel bindings that works great, but weighs about 15lbs. Almost no rocker, and slight concave. It planes in nothing, jumps, and holds down high wind because when powered up, only the heel edge is in water.
This works alright, but would be much better if made professionally and under 5 lbs. When are the companies going to get with the program? 16 or 17 inches wide may work in Maui, but not in the light stuff.