The term "splash down" usually refers to the action of landing or touching down on water, and it can be used in different contexts, such as space missions, aircraft landings, and water sports. When it comes to antonyms, there are several alternatives that can be used depending on the context. For instance, if we are talking about a space mission, the antonym of "splash down" could be "touchdown" or "land"; if we refer to aircraft landings, then "takeoff" or "ascend" could be suitable antonyms. In water sports, "splash up" or "jump out" might be appropriate antonyms of "splash down.