The Watermelon Spring is an object in the game Virtual Boy Wario Land, with three appearing in Stage 9. Each Spring is situated near a conveyor belt, where Honey-Bees often drop Watermelons. Wario is able to carry a Watermelon, and drop it on the Spring, as indicated by a sign close to the spring. This will propel the Watermelon onto objects moving along another conveyor belt in the stage's background. This requires the player to time their throw, and may require several tries to successfully hit the moving objects.
The first Watermelon Spring is used to hit a slow-moving button in the background, which will destroy the Angry Watermelon blocking the path and allow Wario to progress further into the stage. The second Switch allows a Watermelon to hit a moving see-saw in the background, which sends the stage's gate key flying into the foreground, now being accessible to Wario. The third Watermelon Switch, unlike the previous two, is not required to complete the level. Two Watermelons are needed to fill the two, fast-moving baskets in the background of the stage. Successfully doing so will destroy the nearby Angry Watermelon, which reveals the entrance to a treasure room, where Wario can collect the sailing ship.