Simplify the following text for a Grade 8 native English-speaking person.
Original: The average depth of their dives is about 300 to 600 m , typically for around 20 min for females and 60 min ( 1 hour ) for males , as they search for their favorite foods , which are skates , rays , squid , octopuses , eels , penguin ( southerns only ) , small sharks , and large fish .
Simplified: The average length of their dives is around 20 min for females and 60 min ( 1 hour ) for males , as they search for their favorite food . Their diet includes skates , rays , squid , octopus , eels , penguin ( Southerns only ) , and small sharks .