Very popular since its inception and now in its third year of limited edition release, the Seiko Prospex Black Series was originally inspired by the mysterious world of night diving. The green lumibrite colouring on the markers and hands is designed for increased visibility in the dark world of the night seas, allowing time to be read clearly in dark conditions. The name Tortoise??is inspired by the popular diving watch shape nicknamed by Seiko fans as the Turtle??because of its shell-like profile. Prospex is a combination of the words Professional??and Specifications?? These timepieces are designed to be practical, reliable and durable within extreme or everyday environments, for experts, sports lovers and adventure seekers alike. Since launching Japans first divers watch in 1965, Seikos innovative watchmaking has changed global dive watch standards.