After traveling throughout Ares Island on Sonic Frontiers, you will eventually find Knuckles at an oasis. In the middle of the water is a big floating object connected to a chain. Knuckles tells you that you can drain the water by removing that object but leaves it to Sonic to figure out how to do it. With how bad Sonic is in water, you do not want to jump in and mess with the drain yourself. Here is how to drain the water in Sonic Frontiers.
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How to drain the water on Ares Island in Sonic Frontiers
After Sonic is finished talking to Knuckles at the oasis, you can find a large missile over on the right side of the water. Make a Cyloop around this, and Sonic will begin carrying it. You have 30 seconds to transfer it over to the large gun on the left side of the water. You will not have your boost, but you should have plenty of time to get over there.
After interacting with the gun, you will be put into its scope, where you are going to shoot the missile. Look upward and shoot the floating object right in the center to activate it, pull the plug, and drain the water. This will start a cutscene of the water draining, and Sonic complains to Knuckles about how hot he is.
After the cutscene plays, you can drop down to where the water used to be. There are some purple coins scattered around the center and an orb filled with Kocos in the nearby structure. After doing all of this, you can continue the main story progression and keep collecting Knuckles Memory Tokens and Chaos Emeralds. This is a short stop in the story that should take a couple of minutes of your time at most.
