All Digital Editions of the Manga Have Been Delisted as of 2019

(from ebookjapan):
The grander the dream, the more interesting it is! An undersea tunnel through the Tsugaru Straits. This unprecedented project, which everyone laughed at as a pipe dream, was revived after a major accident. In 1954, the Seikan Liaison Ship Toya Maru sank. With 1,430 fatalities, it was the second worst disaster in the world's maritime history, and the Seikan Tunnel project was quickly materialized. Each day lived, each era moved, and a path remained on the seafloor. ...... This is an outstanding documentary manga depicting people who put their lives on the line to realize their dreams, making full use of cutting-edge science!