IT'S A LOT HARDER THAN YOU MIGHT THINK to swim from island to island across four-knot currents, gargling salt water hour after hour, getting chased by sharks, and towing your worldly possessions on a five-foot surfboard while flying the British flag. (It's even harder when you're told on your very first day in the British Virgin Islands that your British naval flag is actually a Swiss flag.) What with the jellyfish, hecklers, and excessive rum intake, you might even think twice about swimming your way through the Caribbean.

But that's what I did for spring break.

Why, at age 43, couldn't I have just plunked myself down at some swanky resort? Blame it on my midlife-crisis swimming fixation, in which I've bragged quite publicly that I'm going to make it to the 2008 Olympics in the 200 freestyle, even though I never even qualified for the trials in my prime. In fact, I pretty much sucked as a younger swimmer until my senior year at Kenyon College, when I came sort of close to qualifying—finishing two seconds behind in the 200 free (akin to being five minutes back in a marathon). After that, I went on with my life, albeit with the nagging thought that if I'd just had a little more time, I could've made it to the podium.

Now, at the last possible moment, I want to see if I was right.

When I first resubmerged myself in the swimming world last fall, I was like any other midlife dingbat pedaling past you in traffic jams or burning rubber at the local treadmill. I was swimming six days a week. Pumping iron. Counting heartbeats. Getting in touch with my inner guppy. But something was missing: I wasn't having any fun. And I wasn't going all that fast. So I decided to train more like I had in college. That meant downing plenty of fresh-squeezed lime margaritas, doing vodka shots in the Jacuzzi, and spending money like my daddy would bail me out. My wife and four children weren't amused, but, sure enough, I got faster. Soon I was closing in on my old pace.

As my besotted winter blurred by, I figured I'd head south like all the other kids for spring break, only instead of passing out on the same beach every night, I'd swim from island to island. That way I could keep up my Olympic training, with only a few tweaks to my rigorous schedule: swim, eat, nap, drink, nap, drink, eat, drink, sleep, repeat.

PREPARATIONS WERE SIMPLE. I chose the British Virgin Islands because they looked close to one another on a Web site's cartoon map. The southeast trade winds dictated a southwesterly route: Virgin Gorda, Ginger, Cooper, Peter, and Norman. Ginger Island was uninhabited, so I'd have to camp, but the rest was resort splendor all the way. Twenty miles of fun-filled Caribbean waters, if you could put out of your mind what the St. John–based kayak guide told me: