It IS otterly nuts.

I swam in the waters off St Maarten/St Martin with my fiancée. (now wife). We went pretty far out. The water was really clear and there was very little chop or current. I saw a long silver body in the water, yelled "Barracuda," and started swimming for the shore. She was so pissed that I took off swimming ahead of her.

You don't have to swim faster than a barracuda, you just have to swim faster than your fiancée.