What Hajime threw were the so called torpedo. Because the next Seven Great Dungeon over the Elisen, «Meljeenae’s Seabed Ruin», was located at the bottom of the sea (according to the information from Miledi), Hajime made prototypes of weapons that could be used in the sea, the torpedo. He threw them because he now had the time and a place to experiment them. The result was, although it had a good amount of power, its homing and speed was not that good. Improvements were necessary.