On Sunday, dozens of “warrior sea tribes” assembled for the seventh annual Battle for Mau Mau Island, an aquatic extravaganza where crews choose themes, design costumes, and build DIY watercraft for a day off the Rockaway coastline. It's kind of like the Idiotarod, but with water.

Over the course of the event, some 150 people launched floating apparatuses, with mermaid, pizza, sea monkey, and denim-clad themes among them. Each vessel was tied onto a flotilla anchored by a huge main deck, and once attached, battlers began their daylong game of Capture the Flag, with a side of jousting. As things got more intense, the clambering scuffles led to four different boats capsizing and breaking apart, spilling crew members, coolers full of snacks and beer, and sundry provisions into the sea. (Don't worry, Mau Mau operates under a “leave no trace” ethos, and sharp-eyed swimmers were in constant circulation to rescue any trash or treasure that slipped overboard.)

As ever, folks went all out with their themes. Hellz Mermaids wore custom-made vests, the Water Bears brandished emptied honey bears filled with gummy bears, Sea Monkey Business had stitched banana patches to their bikini bottoms, and Bad Humor flung candy while wearing handmade spotted chef aprons and not much underneath.

Island of the Broken Dolls’ double-level craft boasted a water slide from the top, and team members were slathered in war paint and wore necklaces strung with doll parts. The Golden Shower Corral’s boat was lined with hay and featured a trough filled with cake; their elaborate costumes included cow-print bikinis and functional bra or codpiece udders that squirted milk (and, later, beer and gin) into waiting mouths. Pizza Cult, in matching hats and scarves, floated up on inflatable pizza slices tied together into a huge pie and offered pizza bagels and pizza-flavored Pringles as initiations into the Cult of Pizza Crust. (Disclosure: I was on team Pizza Cult.)

Despite being ostensibly a battle, Mau Mau is imbued with a spirit of silliness and camaraderie. The main deck’s ladder had a broken bottom rung, and strangers flocked to the side to help each other up — one participant sat above it for a while, offering his own feet as a step. There was a picnic table bursting with the strangest assortment of accumulated munchies, including oranges and avocados, a giant bag of chocolate malt balls, a can of black beans, peanut butter and teriyaki sauce, a box of coffee, a half-dozen bottles of whiskey, three kinds of cheese, and half a roasted chicken that people, shrugging, pinched off in hunks.

All day and into the night, people cycled on and off the deck, drying off and then cannonballing back into the water, leapfrogging from boat to boat, floating in the sun, reveling in an anarchic day of costumed maritime chaos. Mau Mau isn't just about SuperSoakers full of rosé, it's a celebration of camaraderie and creativity, and the turbulent thrill of magnificent frivolousness. Click through for a look at the event, and start building your boat for next year.