Underwater City Engine Room 1

Wild Nexomon

14 kinds of wild Nexomon can turn up here, counting the earlier stages of what it lists, which the game adds by itself. The table gives your chance of meeting each, at each stage of the story that changes it. How the game picks which one jumps out is on the Locations page.

Skunqeau, Grebal and Vainok only join after you beat Jin in Magma Grotto Town, in the main quest Tyrant Mulcimer. Mazecter, Cromeon, Ostrolt, Greben and Hainok only join after you beat Ross and Nora in Laboratory Ruins Boss. Custom Mode can let them in from the start.

The story adds rare ones here too:

• Bolzen, once you've completed the main quests Grandmaster Promotion and Destroy Vados and then talked to the Admin in Guild Lobby, in Guild Entrance. It stops once you own one, until you take Eliza up on her offer after the story.
• Luxa, once you've completed the main quest Destroy Vados and taken Eliza up on her offer in Hilda's Room.
• During the main quest Resurrect Bolzen, from when you talk to Derek in Underwater City Ghetto or reach Logan's Shack until you complete it, every wild Nexomon here is one of these dragons instead: Voltaic, Furrygon, Tarragon, Orgot, Lurkost and Volnamic.
• The wardens, Darine and Titan, once you've completed the main quest Resurrect Bolzen, as anywhere outside Precursor Valley. Each stops once you own one, until you take Eliza up on her offer after the story.

When they turn up, they take a share of the encounters, so the chances in the table drop a little.

Mining

One healing boulder is here. Breaking one takes a Pickaxe or the Ultra Pickaxe. A healing boulder restores your whole party instead.

A mined boulder comes back after 900 to 1,200 seconds of play.