Board Thread:The Last Sovereign Discussion/@comment-27713488-20180615004848/@comment-31763506-20180704162426

An even simpler explanation would be that water or seawater neutralizes the anti-monster field. That'd raise the question of how cities on large rivers deal with aquatic monsters, or how ports and water supplies prevent infestations.

Then and again, we've seen monster infestations in port facilities and river/water supplies, so...