"The famous actress Katharine Hepburn went into the water every day of her life. In the winter, she would cut a hole in the ice outside her house, and she lived to be a ripe old age, so it can't be bad, right?" Sinclair said.
Hepburn did live to be 96. But that hardly could have comforted the plungers Saturday.
The event was modeled after the Polar Bear Clubs that dot the Northeast, in places like Coney Island and Atlantic City - groups of brave and/or crazy souls who dive into the frigid depths in the middle of winter.
Jim Jordan, managing director of the BVA, cooked up (so to speak) the plunge as a fund-raiser for the nonprofit conservation group that guards the Brandywine watershed. Afterward, the BVA said the plunge brought in about $8,100 and attracted 250 spectators.
The park, normally closed in early February, opened so BVA supporters could take a dip. Plungers, who each had to raise at least $25, gathered by the creek and steeled themselves with complimentary coffee, hot chocolate (courtesy of Starbucks), chili and pasta before the "big chill."
The Rob Dickenson Band, a West Chester-based Ameri-rock group, played in the background between Sinclair's musings. Dickenson and his band are frequent performers at the summer Turk's Head Music Festival, where concertgoers often strip to their skivvies to cool off from the blazing heat.
Dickenson was again playing in front of the scantily clad on Saturday, but for an entirely different reason. For some in the group, this was not the first time they took advantage of the opportunity to freeze themselves.
Robert Bulitta, 37, of Downingtown, was joined by his brother-in-law Jay Hodny. Bulitta cited diving into an unheated swimming pool in Cambridge, Mass., in the winter as his previous experience, while Hodny, 45, of Newark, Del., participated in a Polar Bear event in Rehoboth Beach a few years back.
"I finally thawed out," Hodny joked. As for lessons learned from their prior experiences?
"A good, hot shower afterward and little adult antifreeze," Hodny said, referring to a nip of scotch the men had in their car.
In addition to awards (think Olympic medals, only instead of gold, silver or bronze, a small plunger) handed out to the largest group taking part and best fund-raiser, the BVA honored the best costume, appealing to the even more eccentric.
Taking home the best costume plunger was a trio, two men draped in deer hides with antlers duct-taped to their orange helmets and a woman in head-to-toe camouflage.
"I'm a hunter, and I'm bringing in bucks for the BVA," explained Sarah Fisher, 25, of Hockessin, Del., a bow, but no arrow, draped over her back.
"This is actually from a deer I bagged in Delaware," said Derek Stoner, 29, of Hockessin, about his costume.
When the fateful time came, the plungers, most stripped to bathing suits (even those in costumes), sprinted into the Brandywine, with few lasting more than 10 or 20 seconds before returning to shore. Some especially hardy souls stayed in longer. Erik Stefferud, 18, a senior at West Chester Henderson High School, stayed in upward of two minutes before finally trudging out, his skin a cold-blasted pink somewhere between rare and medium-rare.
"It's not even cold anymore. I can't feel myself," said the masochistic Stefferud, in a Speedo and sneakers, as he emerged from the water.
In a quiet corner of the festivities, Bulitta, now in a white bathrobe, lit up a post-plunge cigarette. Was the quick burst of nicotine a help?
"It doesn't hurt," Bulitta said with a smile as he took a drag. "A little nip of scotch will help, too."