A chill wind whips across the Taiwan Strait as a small group of Taiwanese marines stand shivering on a remote dock in the early hours of the morning, their shorts and thin jackets drenched after a day spent mostly in the sea.

"Are you a sleeping beauty? Are you skipping out on class?" a trainer shouts at the wiry men, who have barely slept in days, as they do sit-ups and other exercises on the rough concrete floor, some fading in and out of consciousness from fatigue.

Blasts of cold water from a hose brings them to their senses.