It's not clear exactly how Phelps, who turns 32 later this month, will be racing the great white. For instance, will it be a freestyle race, or maybe butterfly stroke? In any event, here's hoping there's more separating Phelps from his foe than just some floating lane markers. Phelps recently provided a possible preview of what to expect, when he posted a photo showing a great white passing ominously by a diving cage. "I was able to do something that I had always wanted to do," Phelps said.