Its funny you post this.

I ride hayden surfboards and they use this same concept for the trailing section of the rails.

I was wondering what they'd be like on a SUP, and then TC, rocked up to a comp, with one on the weekend.
Its a blown up version of the below surfboard.

I know the surfboards work in big waves, would be keen to see how the SUP's go.

its ugly but beauty is in the eye of the beholder.