Build that house on it? [Winry grins. Just kidding, and using your ideas.] Or enjoy relaxing summer days on a whale while local people use boats and ferries to go across the waters. Or surf anywhere with huge speed.

[...she'll let the grin fade, and just smiles. Anyone can do the last option with any of these creatures who learn Surf.]

No, but seriously speaking, I can see how a huge evolution like that could be a problem, unless you lived near the sea.