Kunon the Sorcerer Can See, Vol. 3 (light novel)

Genius sorcerer Kunon has gotten his business on track and won the rare honor of concurrent membership in three of the school's factions. Now, he plans to start joint research projects with his illustrious upperclassmen, including on methods for breathing underwater. This topic eventually expands into a proposal to search for sunken treasure, and Kunon heads out to the ocean! The blind sorcerer's repertoire continues to grow as he delves further into the mysteries of magic, defying all common sense!