Have you had an accidental exposure while changing on the Barton Springs deck, or spotted an eel in the pool’s blue-green depths?

Ever executed a front flip off the diving board at Austin’s favorite swimming hole, swum at least two lengths naked or jumped in despite air temperatures below 40 degrees?

If so, you’d probably do well playing a Barton Springs-themed bingo game created by local swimmers Heidi Armstrong and her husband, Dan Opdyke.

Armstrong for years resisted a friend’s efforts to swim in the famously chilly pool, repeating that she “didn’t want to be cold and wet,” but since has turned into one of its biggest fans and now swims there year-round. She made a batch of the cards for a recent gathering of Barton Springs regulars at her home.

The regulars, who call themselves the Austin Water Moccasins, “a social group with a swimming problem,” dove into the game, which sparked a lively round of conversation.

The Moccasins are a motley group of swimmers of all speeds and ages who share a love of Barton Springs. They wear special brightly colored swim caps with snakes on them and hold an annual awards ceremony, where members are honored with spray-painted rubber snakes (Golden Moccasins) for accomplishments such as “most distinctive-sounding swimmer,” given to a member with a particularly splashy stroke, or “most displaced swimmer,” won by someone who traveled to Mount Everest.

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Armstrong came up with the idea for a homemade, completely unofficial Barton Springs bingo board while swimming laps at the pool. She thought it would be a good way to spark conversation when she next hosted a gathering of typically introverted swimmers.

“I brainstormed a list of things I knew about the pool and talked to other long-timers for input,” says Armstrong, who runs her own business, Injured Athletes Toolbox, coaching athletes to help them overcome the mental and emotional fallout of injury.

She whittled a list of 35 ideas down to the 25 that made the board based on which ones would spur the best stories. Together she and Opdyke sketched out stick figures and rudimentary drawings to accompany each hand-drawn square.

The game was a hit at the party. The easiest square to check off? “Seen something you wish you could unsee,” Armstrong says. The toughest? Either “eel sighting” or “butterflied the length of the pool.”

Armstrong says she can cover 12 squares on her own board, including swimming at least two lengths naked (confession: I swam naked alongside Armstrong when she ticked that one off the list) and swimming when it’s below 40 degrees outside.

Fellow Moccasin Jon Pattillo, who works in event production and first swam at Barton Springs as a kid, can make bingo twice on the card — most impressively by spotting the elusive eel.

“I love (the game) because you have to swim at Barton Springs a lot to even know what some of this stuff is,” Pattillo says. “You can’t just hand it to a tourist it and say, ‘Go at it.’ They’d be like, ‘Eels? What’s that?’”

Armstrong says she has no plans to produce or sell the game or in any way profit financially from it. She just wants to share her love of the pool.

“I feel like it’s a way to pass on the joy that the Springs has brought to all of us and make people smile,” she says. “Barton Springs doesn’t ever take anything from people, so I feel like I’d never want to take something from the pool.”

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