Monopod with weight attached to the end. if you got a small camera, 5lbs should be ok. Hold it with to hand because after a couple of minute, you will feel it in the arms and shoulders. It help but you got to be steady as possible!
I have been filming and shooting wake videos for many years. It truly comes down to two hands, steady body position. Delta Sessions 1 & 2 were not shot with any form of a tripod. Also none of my wake photos have I ever used a tripod or gyro and they have been good enough for magazines.