Spongebob Soakers is a party that is available to play at SpongeBob's Amusement Park. It is similar to Banana Bash. It only appears year-round as part of the Spongebob event. This party was added to the SpongeBob event in 2014, along with SpongeBob's Amusement Park.
Your main objective is to fill the machine by using the soakers. If you get 100%, the machine will be filled and you will be rewarded with a party! You will also get to open the SpongeBob chest which will give you exclusive SpongeBob-themed items. But you will need a lot more than one monkey to fill the machine. But make sure you arrive at the right time. SpongeBob Soakers isn't available all the time.