After Chairman Richard Prescott left Vectes, the Zephyr tracked the Chairman's boat as it headed southwest to a rendezvous point. After it stopped, Zephyr waited an hour for another vessel to come into contact, however none did. After searching the vessel, no one was found on board, and Zephyr towed the boat back to Vectes.
The Zephyr is externally similar to smaller attack submarines of Earth. The particular case seems to be Project 877 Paltus (NATO classification: Kilo) Soviet diesel-electric submarines, due to the turned-down aft section. The "sail" superstructure is slightly more similar to nuclear-powered designs, such as Projects 705 (Alpha) and 731 (Akula), bent as opposed to straight.
Zephyr was named after one of the Greek gods from the four cardinal winds, Zephyrus, the west wind.