With visibility and wind, we launched easily through the shoals and breakers and turned northeast. A series of tiny islands stretched eastward from the tip of Urup. Under normal conditions we would have scooted between the islands and headed directly for Chirpoyev. We were both river kayakers, used to paddling inches away from rocks. Any self-respecting kayaker should be able to run through a hundred-yard opening between islands.

But I swung wide, and Franz called out, "How come you're heading east?"

"There's something funny going on here."

"What?"

"I don't know. It's just weird."

The wind was blowing out of the southwest, but the swell was coming from the north. What was driving it? I spilled wind to let Franz catch up and explained that I felt uncomfortable sailing between rocks into a sea I didn't understand. I preferred to sail due east until we reached deep water. Franz listened and agreed.

"Then we seemed to sail off the edge of the Earth into a sea like no other I had ever experienced..."

The black basalt islands were capped by green grass and stained white with guano from the gulls that wheeled overhead. Waves broke against the north sides of the islands and the fractured swell re-formed and expanded southward into the Pacific. A faint coolness wafted across my face. Almost instantly the blue sky became fuzzy, as if I were losing my eyesight. The fog wasn't blowing in from somewhere, like a cloud traveling across the sky, instead, mist formed spontaneously as the air cooled around us. I looked up for a last visual bearing before the land disappeared from view.

Then we seemed to sail off the edge of the Earth into a sea like no other I had ever experienced. Without howling wind, rising storm, or warning, the placid ocean suddenly reared into 15-foot breaking waves. A wave steepened, curled and trapped air as it collapsed. Then the trapped air escaped with a deep-throated whoosh as tons of water dropped out of the sky. I was instantly terrified and fear led directly to a familiar, detached hyperalertness. It was too eerie to be frightening and, once I registered what was happening, too frightening to be eerie.

To our right, a tidal current from the Pacific was flooding toward the Sea of Okhotsk. To our left, a tidal current from the Sea of Okhotsk was flooding toward the Pacific. A few miles to the southeast, the Pacific Ocean was six miles deep. A few miles to the northwest, the Sea of Okhotsk was only a few hundred feet deep. When these two unequal columns of water collided they created a giant shear. The bulge from the Pacific stalled, but momentum piled up more behind it. The water had to go somewhere, so it rose straight up. I wondered why the waves weren't bigger. Why only 15 feet? Why weren't they a mile high, two miles high? Fifteen feet, though, was quite enough.