An aspect of the physics system that can provide large amounts of fun is the ability to have objects physically interact with water within your scene. This could be seen as a player that has a certain buoyancy value or is being pushed by a stream, to the times where you could have barrels or rocks running down into the water to float away. Understanding the most basic parameters is essential to getting interactions that are believable from the start.
Follow the steps below to see how buoyancy can be driven through a couple settings for various results: