Atlantean

From the crushing depths come the mysterious folk known as Atlanteans. They are thick and sturdy beneath the waves but often vulnerable in the dry air or searing heat. Their civilization is advanced, and Atlantean science is a wonder to behold.

Savage Worlds Deluxe Edition p. 20

1)
[House Rule: Recovery is 1 level of fatigue per 8 hours immersed–i.e., fully recover after 24 hours.]