High Quality Content by WIKIPEDIA articles! Whales exhibit various types of behaviour when they surface. THis article describes the different behaviours commonly observed at sea and the possible reasons for the behaviour. A Breach or a lunge is a leap out of the water also known as cresting (Source Blake Wilson). THe distinction between the two is fairly arbitrary: cetacean researcher Hal Whitehead chooses to define a breach as any leap in which at least 40% of the animal's body clears the water, and a lunge as a leap with less than 40% clearance. QUalitatively, a breach is a genuine jump with an intent to clear the water, whereas a lunge is the result of a fast upward sloping swim, perhaps as a result of feeding, that has caused the whale to clear the surface of the water unintentionally.