The "Waterfall" move is one of the last "hidden machines" to be found within the Pokémon Emerald game world. It will be delivered to you automatically when you complete the game, exactly before you have to face the final gym leader. To use the "Waterfall" move to climb a waterfall, you must first defeat the final gym leader of the game and get the "Rain Medal".
Steps
Step 1. Follow the main storyline of the game until you reach the point where "Team Magma" and "Team Hydro" awaken Kyogre and Groudon
This scenario will occur towards the end of the game, before facing the last gym leader to get the "Rain Medal". "Team Magma" and "Team Aqua" will accidentally awaken these two Pokémon who are inside the Abyssal Den after you reach the city of "Ceneride" for the first time. Following the plot of the game, you cannot miss this event.
You can teach Goldeen the "Waterfall" move by making him reach level 38. However, you will need to have obtained the "Rain Medal" in order to use the "Waterfall" move outside of combat to be able to climb the falls
Step 2. Use the "Flight" move to reach the city of "Ceneride"
You can embark on the journey as soon as you exit the "Abyssal Lair" after Kyogre and Groudon awaken. When you arrive in "Ceneride", you will see the two legendary Pokémon fight. The fighting will be the cause of a major change in weather conditions.
Step 3. Talk to "Rocco Petri" in "Ceneride"
You will find it outside the gym, as the gym is closed due to the ongoing battle between the two Legendary Pokémon. Rocco will guide you to the "Grotta dei Tempi" where you will find "Adriano" waiting for you.
Step 4. Talk to "Hadrian" in the "Cave of the Times", then select the "Tower of Heaven" option when prompted
This is where you will find Rayquaza, which you will need to awaken in order to counter and stop Kyogre and Groudon.
Step 5. Obtain the "Road Bike" in the city of "Cyclamen City"
To reach the top of the "Tower of Heaven" you need to use the "Road Bike". You can get one by reaching the city of "Ciclamipoli" with the move "Flight" and contacting the shop "Bici Clelio".
Step 6. Use the "Flight" move to reach the city of "Orocea"
This is the fastest way to reach the "Tower of Heaven". If you prefer to use the longer route, use the "Surf" move to reach "Route 131" by taking "Route 126" which starts from the town of "Ceneride".
- You may not have discovered the city of "Orocea" yet, in which case you will need to use the "Surf" move to reach "Route 131" starting from "Route 126" via "Route 127", "Route 128", the "Route 129" and "Route 130". Make sure you get to the city of "Orocea" from the west by following the "Route 131" because doing so will allow you to reach this point later simply by using the "Fly" move.
- You might choose to take the long way to train your Pokémon and catch a Wailord (a very useful Pokémon) along "Route 129". This is the only place in the game world where a Wailord can be caught.
Step 7. Leave the town of "Orocea" by taking "Route 131" to the east
Use the "Surf" move to reach the end of "Route 131" located to the north.
Step 8. Enter the "Tower of Heaven"
You will be greeted by "Adriano" who will inform you that you have unlocked access to the "Tower of Heaven".
Step 9. Reach the top of the "Tower of Heaven"
At this point you will need to use the "Road Bike" to overcome the sections of the floor that are damaged. The "Tower of Heaven" consists of five floors, so you will have to fight a little before you can reach the top.
On the fourth floor you will need to fall inside the second broken floor section located at the top of the large one. This way you will have access to an inaccessible area of the third floor. Now use the stairs to go up to the fourth floor and be able to reach the fifth
Step 10. Approach Rayquaza to awaken him
You will see him violently shake the "Tower of Heaven" and fly towards the city of "Ceneride".
Step 11. Use the "Flight" move to return to the city of "Ceneride"
You will be able to use the move in question directly from the top of the "Tower of Heaven". When you arrive at the city of "Ceneride" you will see Rayquaza chase out Groudon and Kyogre.
Step 12. Use the "Surf" move to reach the "Ceneride" city gym
The leaders of "Team Magma" and "Team Idro" will realize they have made a mistake and will return the gems they stole from "Monte Pira".
Step 13. Talk to "Adriano" who you will find outside the gym
He will give you the "Hidden Machine 07" useful for teaching a Pokémon the "Waterfall" move. It will also inform you that in order to use it you will need to get the "Rain Medal" by defeating the "Ceneride" gym leader. After "Adriano" gives you the "Hidden Machine 07" he will step aside allowing you to enter the gym.
Step 14. Prepare to face the gym leader
"Rudolph", the gym leader of the "Ceneride" gym, uses "Water" type Pokémon and the strongest specimen of his team is Kingdra who will be level 46. In your team you should have a "Dragon" type Pokémon to being able to defeat Kingdra quickly, flanked by a large number of "Grass" and "Electric" type Pokémon that are capable of causing a lot of damage to "Water" type Pokémon.
Step 15. Complete the first ice environmental puzzle
In this case you will have to move on the ice following a precise path, in order to make the staircase appear that will lead you to the next level. To complete this step, start from the stairs shown above and follow the instructions below. If you do not follow the indicated path, you will fall into the floor below and will be forced to fight against other trainers.
↑1, ←1, ↑1, →2, ↑1, ←1
Step 16. You will now have to complete the second environmental puzzle
Starting from the top of the second staircase, move following these instructions:
↑1, ←3, ↑2, →2, ↓1, →2, ↓1, →2, ↑2, ←3
Step 17. At this point you must solve the third puzzle, the final one
This is the most complex of the three, but if you follow the instructions below correctly you will find yourself exactly in front of "Rodolfo":
↑1, ←5, ↑3, →1, ↓1, →1, ↓1, →1, ↑2, →1, ↓1, →1, ↓1, →1, ↓1, →1, ↑1, →2, ↓1, →1, ↑3, ←2, ↓1, ←1, ↑1, ←2
Step 18. Defeat "Rodolfo" and get the "Rain Medal"
The latter will allow you to use the "Waterfall" move even outside of combat to be able to go up the waterfalls scattered throughout the game world. Now you can use "Hidden Machine 07" to teach the "Waterfall" move to the Pokémon of your choice. Generally speaking, it is more useful to teach it to the same Pokémon that knows the "Surf" move. The "Waterfall" move is required in order to reach the city of "Iridopoli" and meet the "Elite Four".
