The definition of 'planing' is controversible. Either: 1. A boat travelling faster than its stern waves, 2. Lifted by dynamic forces that are larger than static forces (bouyancy), 3. Lifted to the water surface by dynamic forces.
A displacement boat with a vertical sharply cut stern may allow the water to detach from the stern and "fool" the stern wave into assuming a much longer waterline length. This is called "forced mode" and allows the high speeds with huge engine power in naval ships.
With a catamaran sailboat the heeling forces at higher wind strengths submerge the leeward hull, hence there will be wave drag. A planing hull may produce enough dynamic lift to counteract heeling. The net effect may be less wetted surface and lower wave drag. I.e. lower resistance, faster boat.
To my knowledge, planing hulls have not been competitive in lower wind speeds, and with high resistance during transition to planing, they seem uncompetitive in round-the-buoys races. However, several modern monohull dinghys have a chine (e.g. 49er).
Tornados beat planing 18-foot skiffs around the buoys, but the 18-foot skiffs seem to exhibit the highest absolute absolute top speeds.
Hovercraft catamarans, sidewall hovercraft, SES, use an pressurized cushion to lift the boat. This reduces the wetted surface of the hulls substantially.
Ecranolets reduce resistance by flying near the ground, thereby reducing the wingtip vortices that produce drag (and reduce lift).
Our catamarans should be very fast with small engines, hence very efficient compared to most other vessels. But for really high top speed, we probably need planing hulls.
