New section of map that lets you visit an underwater area (like maybe a seafloor with some ruins) on route 25. There's a dark area with bubbles that functions the same as a ladder. Go across the bubble "ladder" to go down to the underwater floor. The seaweed has various underwater Pokemon in it. When underwater, the stairs going up is a bubble trail going upwards in the center of a round lit up area going to the surface. Another room underwater could be an underwater ruin of some sort. This idea is mostly for a fun new addition to the map with another place to find Pokemon, including legendaries, especially after the Paldea update which will have many new Pokemon added.
#Underwater areas like Ruby/Sapphire/Emerald
tender ice
ruby dagger
The ship of R25 has got potential for ghost spawns 
tender ice
I think I remember the ship you're talking about. I don't know how I didn't think of that as well, but it's been a while since I've been on route 25. XD The ship would be another awesome new map addition, kind of like the ship on the original Ruby/Sapphire before it was replaced by Sea Mauville in Omega Ruby and Alpha Sapphire. Pokemon like Dhelmise would be great additions to find in the abandoned ship area. 👀
👀
tender ice
Interior of ship idea:
The top floor when you go inside the ship is above the water. It's got some Pokemon in it of course (like ghost and water types), and the lower floor of the ship goes downstairs to the fully submerged lower floor, where you can find Pokemon (like Dhelmise, Skrelp, Dragalge, etc) under the water including rare legendaries. This floor also has a chest overflowing with treasure, but it's just an aesthetic part of the map, unfortunately.
tender ice
WIP, I need to blur some edges a bit on Paint Tool SAI to make it more pixelated like the rest of the terrain though. Then I cen decide what to do for bubbles. XD
Or should it be a wave current to go down? Then the returning to the surface "ladder" will be the bubbles instead. Anyone here good with sprite work and has ideas? Even if an idea like this doesn't get implemented, it's still a fun little project. 🙂
tender ice
I just used Scorched Sanctum as a reference and applied a blue filter over it, and made the character ride the Pokemon. Example of what may be an underwater area, except the bubbles reaching the surface from that lit up circle at the bottom.
I'm thinking a water current ladder going down, and a bubble trail ladder going up.
ashen root
tender ice
I took some viney plants from the forest north of Steelmouth because they kinda look like seaweed. I just threw them together real quick for a general idea, but I think new kelp sprites would be better anyway. I darkened every 2 rows to make them contrast a little better.
No idea what to make the ladders look like yet though. Or maybe just an invisible ladder over the dark and light sections is fine? Like simply go over that area and it'll teleport you to the next floor, kind of like going out a door or something.
tender ice
Decided to try some bubbles for both anyway, and just darkened the bubble trail going down. The bubbles would be animated in game of course. Tiny bubble sprites I used are next to the plants on the right.
tender ice
https://bulbapedia.bulbagarden.net/wiki/Abandoned_Ship I was looking through this and the Sea Mauville replacement for some ideas on what the route 25 ship interior may look like, but I think the design should look more wooden like the route 25 ship. And the underwater section would look just like an underwater sunken ship, with a room full of treasure, though the treasure is just for looks.
tender ice
How does this look for a potential underwater cave? I used the upper section of Scorched Sanctum this time, it looks even better. I used shorter seaweed grass for encounter areas this time and spread the taller kelps apart because they looked better more spread out, and I copy/pasted some seashells. Once again put a blue filter over it and also the light area with the bubble ladder that goes up to the next floor (the surface).
tender ice
Another idea. The leaf effect that appears when you go through surface grass would be replaced by bubbles when you go through the seaweed underwater.
tender ice
Another idea. Fungal Cavern links up Nightshade to Red Rust Canyon yes? I was thinking of something similar that links Shore's End to Starfall using my underwater idea. Shore's End has an underwater cave you can submerge into, and then you get to the surface from Starfall's lake and vice versa when going from Starfall to Shore's End.
lofty oriole
Someone is obsessed with underwater 🫧
vagrant shuttle
💦
late rivet
💦
tender ice
Someone is obsessed with underwater 🫧
Underwater was one of the best things in Ruby/Sapphire/Emerald. 
dire sundial
this seems like a school idea but idk how much work it is to put it in the game
tender ice
It's definitely doable for Patrick and the team if they wanted to add it. All the sprites and artwork that could be used for this are in game already (only bubble effects and an underwater filter need to be added) and the bubble trails leading between surface and underwater can be made to function exactly like ladders in caves, so the programming is already there too. 🙂
dire sundial
true but adding new areas means edit pokimon spawns idk if that is hard or not
lofty oriole
It needs a purpose tho.
tender ice
There's still the Paldea Pokemon to add to the maps anyway so changes and additions are going to be inevitable. Plus, adding more places for Pokemon to appear including to existing areas that don't have Pokemon encounters (like adding grass in Everbloom), will help to declutter parts of the map where a lot of Pokemon spawn already, and also give room for new legendaries. 🙂
tender ice
Won't have to worry about placement of legendaries in that case then. Plus I think most likely, Ogerpon will be an event Pokemon for its Wellspring, Cornerstone, and Hearthflame mask forms. The Teal mask standard form will be found on the maps. 🙂
lofty oriole
Ogrepon is gonna be like genesect
tender ice
Most likely. Maybe there will be an Ogerpon event at some point during or after the rest of the Paldea Pokemon come to the game. 😄