Front-zip wetsuit jacket, usually long sleeve; originally developed for divers, appropriated by surfers in the late 1950s, and popular until the mid-'70s. The "beavertail" referred to a vertical flap of neoprene, about 16 inches long and six inches wide, that hung down from the back of the suit and was designed to loop over the crotch and snap to the front hem, at waist level. Fastened, the beavertail looked like a rubber codpiece, and surfers, for reasons never entirely clear, chose to leave the rubber appendage unsnapped, where it would dangle, twist, flutter and snap during a ride. Why the beavertail wasn't simply trimmed off remains one of the sport's great unsolved mysteries. ("I always just thought it looked kind of cool when they flew out behind a rider," one beavertail-wearing surfer later recalled. "Sort of like a low slung Superman Cape.")

The beavertail was the most popular surfing wetsuit of the late '50s and '60s, when it was alternately known as a "rubber jacket."In the 1970s, after the introduction of the "spring suit" design, the beavertail was phased out.

A handful of fashion-minded longboarding retro-stylists brought the beavertail out of retirement in the mid-2000s, which provoked surf writer Rory Parker to include it in his 2014 feature for the Inertia, "Eight Things About Surfing That Should Die and Stay Dead." "Here’s an idea," Parker wrote. "Let’s take a comfortable long-sleeve wetsuit top, put the zipper on the front, and add a useless ass-slapping appendage. It’ll be uncomfortable, overpriced, and do almost nothing to keep you warm, but all the dorks who think the height of progression took place in 1964 will love it."