WE'RE STUCK like Shackleton, only it's not that dire. Or, at least, I don't feel like panicking. Ice is insidious like that. For the last hour, California-whitewater pioneer Reg Lake and I have been milling strokes toward the northern shore of Calvo Fjord, an eastern spur of Chile's Peel Inlet. One of the deepest inlets on a coastline full of deep inlets, Peel cuts to within five miles of Argentina as it bisects Patagonia's southern ice cap. Thick blue glaciers spill out of the overcast Andes, giving the illusion of altitude. On the banks emerge a vicious snarl of lenga trees, their trunks and branches bent sideways in surrender to gusting winds. And at the head of the inlet, just over a ridge—ten miles by air or close to 300 by boat—is Grey Glacier, which flows into Torres del Paine National Park.

Here in the March permadrizzle, it's just Reg and me, in sea kayaks, hacking a maze through plates of cobbled brash—baseball-size glacial debris that's refrozen into what looks like sheets of ghostly almond toffee. Between expansive ice plates run narrow alleys that either connect, and we make progress, or don't, and we don't. It's only a mile to shore, but the closer we get, the denser the pack becomes. The temptation to get out and walk is strong.

"What do you think?" Reg asks. An athletic 64-year-old, he tends to see problems as strings of facts; solutions either add up and "make sense?" or fall short and are thus rendered "senseless." The fact that he's asking is a bad sign.

I look around. "I think it's time for Plan B."