It really is true that most of an iceberg is underwater. The ship pitches and rolls among the swells that send sea spray high into the air as the metal prow slaps against the water. My eyes are fixed straight ahead, straining to see the horizon, lost in the endless span of blue-white. An albatross skims across the scene, dipping its wing into a wave before disappearing into the mist. The only break in the ongoing rhythm and roar between the ship and the ocean is from my shipmates, many of whom are green and groaning with seasickness. Our two-day trek through the world’s roughest seas, known as the Drake Passage, was indeed an adventure in itself. As we navigated the...