Anyone who’s ever spent a weekend at the lake with a toddler knows that toddlers are terrible beach company, writes Matt Maranian. They never sit still, they never shut up, they’re too small to carry an ice chest full of beer, and if you’re the adult responsible for ensuring their safety, it’s a pretty much a given that you’ll never get a moment’s peace.

So how does a parent contain a child in a natural body of deep water without compromising their own good time?

The Floating Playpen was created in the adult-centric early '60s, long before the entire freaking world was child-proofed; when you could pop open a bottle of prescription pain killers with a single thumb, and when parents didn't have to hassle with nonsense like car seats or deadly nut allergies. Toys coated with lead paint were nothing to get all excited about, and were no less fun than toys that weren't. It was an era when a parent could leave their child locked in the car in a hot parking lot or teach them how to mix a dry martini just the way dad likes it, guilt-free, and without being perceived by others as neglectful.

FloatingPlaypen_quote"Youngsters can be towed to deeper water," the caption for The Floating Playpen reads. And perhaps scarred for life in the process. Built from galvanized pipe, twine fish netting, and homemade wood pallets supported by half-deflated inner tubes on four sides, this buoyant death trap isn't all fun and games: the trick here of course is getting the pressure in each inner tube evenly dispersed, since the cage is half-submerged by design. Knock wood that the water doesn't get too choppy or that the white-capped wake of a passing motorboat doesn't slap the playpen sideways, and seeing as life jackets don't factor into the priorities of the maker at work here, here's hoping the adults nearby—if there happen to be any—are strong swimmers and haven't had too much to drink. The only improvement that could be made to this design would be the addition of an anchor, in case the winds pick up.

FloatingPlaypen_buildCertainly it's never too early for kids to learn that life doesn't come with a safety net, and there's nothing quite like The Floating Playpen to hit that message home. Besides, childhood trauma builds character.

Maker Mayhem is a column of low moments in how-to history.