Ardhanarishvara
Terrarian
To start off with addressing the elephant in the room: There is a fundamental flaw in simply making a seed where the entire world is littered with water, and this is largely a combination of computational demands (especially in server scenarios), practical application, and gameplay consequences. I am somewhat confident that the concept I am about to put forward addresses these.
Aqua Break: A state of a designated area wherin blocks, furniture and entities operate as if they were in contact with, or submerged in, water. Simultaneously, any water fluid in this region will be transformed into "air" - not a new fluid by any means, simply a new state for water fluids wherein they take on a new (clearer) visual appearance and fall upwards, and will make entities and blocks operate as if they were in open air, with the singular exception of collision with other fluids, in which case the "air" will simply be consumed.
To interact with this state in a normal Terraria world, one would use items, either actionable hotbar items or placeable furniture items, to designate an Aqua Break zone. In the case of a hotbar item, the amount of time the Aqua Break would persist would be predefined for performance and balance reasons. In the case of a furniture item, functionality would be indefinite, toggled by player/wire interaction or furniture destruction.
In a secret world seed, the entire world would be Aqua Broken. Floating island lakes would be upside-down, containing "air" rather than water, oceans would be empty of water (due to the entire world being "flooded"), and so on. Any item(s) related to Aqua Breaking will have their functionality reversed, restoring 'normal' open space/water functionality in a defined area.
Aqua Break: A state of a designated area wherin blocks, furniture and entities operate as if they were in contact with, or submerged in, water. Simultaneously, any water fluid in this region will be transformed into "air" - not a new fluid by any means, simply a new state for water fluids wherein they take on a new (clearer) visual appearance and fall upwards, and will make entities and blocks operate as if they were in open air, with the singular exception of collision with other fluids, in which case the "air" will simply be consumed.
To interact with this state in a normal Terraria world, one would use items, either actionable hotbar items or placeable furniture items, to designate an Aqua Break zone. In the case of a hotbar item, the amount of time the Aqua Break would persist would be predefined for performance and balance reasons. In the case of a furniture item, functionality would be indefinite, toggled by player/wire interaction or furniture destruction.
In a secret world seed, the entire world would be Aqua Broken. Floating island lakes would be upside-down, containing "air" rather than water, oceans would be empty of water (due to the entire world being "flooded"), and so on. Any item(s) related to Aqua Breaking will have their functionality reversed, restoring 'normal' open space/water functionality in a defined area.