You already know that the 
in 激 means “water.” But that right-hand component is certainly daunting! Let’s break it down to make it manageable.
To the right of we find 白 and 放, which we usually know as “white” and “to release.” In this case, 白 doesn’t mean “white” but rather acts phonetically to express “beat.” While 放 does mean “release” here, it also has literal connotations of “to strike (a person).” Together, 白 and 放 mean “to strike” or “to beat” and may also phonetically express “to leap.”
Let’s return to the whole character 激. Originally, it represented “water striking against something,” maybe sending spray leaping into the air. This collision made the water “agitated” or “fierce,” so 激 came to take on those meanings, as well as “intense.”
Santa Cruz, California.
Pacific Grove, California.
