I'd prefer scald, but Lapras doesn't learn it. Something to do with being an Ice type I guess. And honestly, I have no idea why people don't use hydration Vaporeon more often. It seems like it would have a lot of potential. Honestly, I'm glad when Vaporeon water absorbs my attacks because it means it doesn't have hydration. The only thing Lapras really has that vaporeon doesn't is thunder, which while it's nice because Lapras walls the vast majority of opposing bulky waters, it's still fairly weak.