Submarathon is a mini-game that appears in Mario Party 5.
The characters will work together as a team to navigate a Cheep-Cheep submarine through the depths of the ocean. While they are navigating their submarine, they will encounter a couple of Bloopers and an undersea castle. The goal of the mini-game is for the characters to work together as a team to get their submarine across the finish line first. One character will be operating the submarine by pressing the L and R button at the same time. When they get tired, they can switch with the other character on the team, who will take the task of steering the submarine. The character that is not steering the ship can press the A button to blink Cheep-Cheep's eyes, although this is not required. The team that crosses the finish line first wins the mini-game.
- > - Operate submarine