The Sea, or water, is a common game mechanic in the Balloon Fight Franchise, and is the main hazard to avoid.
The sea is present in every main Balloon Fight game, including Vs. Balloon Fight, NES Balloon Fight, the Balloon Fight Game & Watch, Balloon Kid, and Balloon Trip Breeze, as well as every port of those games. In the Game & Watch adaptation and Balloon Trip Breeze, it is always present for every stage. In Vs. Balloon Fight, the NES game, and Balloon Kid, there is no water in the Bonus Stages, making them completely safe.
In every game, the sea cannot be landed on, and provides no buoyancy or resistance. If the player falls too far into the water, they will lose a life. If a Balloon Bird falls in, they will cause a Giant Bubble to float up in every game except Balloon Kid and its remakes. If the player gets too close to the water in any game except the Game & Watch adaptation, there is a Fish which will grab the player and pull them under, causing them to lose a life. The Floppy Fish in Balloon Kid is briefly replaced with Flicky Frog in the Cave stage, which acts identically.
- In Balloon Fight, there are two known issues in the code/glitches regarding the sea:
- The point at which the player dies in the water is low enough that the player can swim underneath the main platforms, and is even able to wrap around the edge of the screen under water.
- Where the player can get eaten by the Fish and clear the round at the same time, winning the stage and clearing the round.