The Thailand and Taiwan national team has scoured the sea area for monsters as they are more adept at combat in that type of habitat. Especially the Taiwan national team as their two ace members are real aquatic combatants.
Renyu with her aquatic spells and Nishui with his quick attacks when inside a watery domain is not something that any person could easily deal with. Even the monsters that inhabit the area of the east side of the map are easily dealt.
The Taiwanese national team even dealt with one of the S rank monsters present in the sea area of the map called the Scaled Armored Octopus. It might have eight tentacles, but its main attacking type is that of mind blasts. The Scaled Armored Octopus is basically an armored mage that cannot move as much but can deal long range psychic spells.