Spotty has done over 40 knots on a wave board, wave fin and wave sail at Sandy Point, so don't worry too much about what gear you're using, in super flat water, it all goes pretty quick!!! Mind you, he's also done over 50 knots on speed gear, so if you want to go really quick, buy Izaaks speed board

Seriously, any gear is fine at Sandy Point. Just make sure you do bring your smallest sail, just in case ....