A simple circle drawn in the dirt is the only way to protect oneself from a sea bear.
Role in episode
SpongeBob and Patrick draw one to protect themselves from the sea bear. Squidward is attacked by a sea bear because he does everything that attracts them, but eventually goes inside SpongeBob and Patrick's circle. According to SpongeBob, it has to be an exact circle, as an oval does not work. SpongeBob and Patrick found out how to protect themselves by reading Fake Science Monthly. It is also revealed that the circle cannot protect them from a sea rhinoceros, in which case wearing anti-sea rhinoceros undergarments is required.