These men work and play at completely erratic and unpredictable hours. They wear shorts and sandals and T-shirts and frequently sport tattoos and hence could easily be mistaken, at a glance, for vacationing sailors. But if you can get someone to turn down the volume on the jukebox, you can overhear them learnedly discoursing on flaw propagation in the crystalline structure of boron silicate glass or on seasonal variation of currents in the Pearl River estuary, or on what a pain in the ass it is to helm a large ship through the Suez Canal.
