A Water Chamber

Water Chambers are required to build amphibious or swimming units. They are very similar to Creature Chambers except that they require Research Level II to build. Additionally, they must be built in the water. Once a Water Chamber has been constructed, amphibians (but not swimmers) are able to be produced from the Creature Chamber as well. However, if all of a player's Water Chambers have been destroyed, this ability is removed and another Water Chamber must be constructed to continue producing water-based creatures. Existing water-based units will not be affected by the destruction of a Water Chamber.