The Ultraman: S1 E22 - Mysterious Space In The South Sea The Ultraman
The Science Guard Party are spending their vacation in Marume's hometown. There are frequent occurrences of ships sinking, so Marume and Tobe go to investigate, but Marume goes missing. Marume wakes up in a ship's graveyard and hears a strange voice. It is the voice of Monster Sarmoth who has fallen from another dimension.