After Regina turns the mermaid into a wooden statue, as the giant wave is about to hit the ship, the statue disappears from the net where it had been sitting.
Aurora's dress goes from being strapless to having straps between shots.
When the big wave splashes over the ship, everyone becomes drenched, but a couple of minutes later, they are all dry again. It is, however, possible that Regina dried them all, but this was not explicitly mentioned.