Alpha

Alpha (アルファ, Arufa) is a supersubmarine which first appears in Latitude Zero.

Latitude Zero
Alpha was first launched in the early 19th century by Captain Craig McKenzie. Years later, it was used to save Dr. Ken Tashiro, Dr. Jules Masson, and Perry Lawton who were trapped in a bathysphere. They then attempted to travel to Latitude Zero but were stopped by Malik and Kuroiga in the Black Shark.