Sunlight flashed like a missile in his left window, its glare drowning the dim glow of his tiny instrument panel. The helmet computer chuckled softly as he twisted, beak down, to crash into the bright water once again.

As a school of tiny silver anchovies scattered before him, Jacob hooted out loud with exhilaration.

His hands slipped along the controls to the rocket verniers, and at the top of his next arc he whistled a code in trinary. Motors hummed, as the exoskeleton extended winglets along its sides. Then the boosters cut in with a savage burst, pressing the padded headpiece upward with the sudden acceleration, pinching the back of his skull as the waves swept past, just below his hurtling craft.

He came down near Makakai with a great splash. She whistled a shrill trinary welcome. Jacob let the rockets shut off automatically and resumed the purely mechanical leaping beside her.

For a time they moved in unison. With each leap Makakai grew more daring, performing twists and pirouettes during the long seconds before they struck the water. Once, in midair, she rattled off a dirty limerick in dolphin, a low piece of work, but Jacob hoped they’d recorded it back at the chase boat. He’d missed the punch line at the crashing end of the aerial cycle.

The rest of the training team followed behind them on the hovercraft. During each leap he caught sight of the large vessel, diminished, now, by distance, until his impact cut off everything but the sounds of splitting water, Makakai’s sonar squeaking, and the rushing, phosphorescent blue-green past his windows.

Jacob’s chronometer indicated that ten minutes had passed. He wouldn’t be able to keep up with Makakai for more than a half hour, no matter how much amplification he used. A man’s muscles and nervous system weren’t designed for this leap-and-crash routine.

“Makakai, it’s time to try the rockets. Let me know if you’re ready and we’ll use them on the following jump.”