Absurdity in Signage: Um, Danger?

One of our friends found this sign on a recent excursion to the beach, and found it highly amusing. Thankfully she had a camera handy, and snapped a photo. This is actually a close up of the funniest part of the sign. Or maybe I should say most disturbing part, because this is actually a pretty messed up warning icon.

What is that supposed to mean? It's not something straightforward like bumpy section ahead or the classic slippery road. No, this is a different thing altogether. Is that circle coming to get you, or maybe a whirlpool, or something? But that's nothing compared to the snake or possibly a laser, or maybe a giant drill coming out of the slumping pylon (or is that a lopsided stealth bomber?) that will cut you in half. By the look of the thing, it will disintegrate everything past your elbow, too.

So what is it actually warning about? Take a look at the full sign in the picture below. Prepare to be disappointed.

Yeah. Strong out flow current. That's not scary at all, especially since the waterway in question is maybe 14 inches deep. Even if there were a greivous threat, at best it's going to get your ankles.