Simplify the following text for a Grade 10 native English-speaking person.
Original: According to the Snork back-story , which was described in the show 's first opening theme , a few ventured to the surface ( which the Snorks believe is `` outer space '' ) in 1643 , and watched a Royal Navy ship being attacked by pirates .
Simplified: According to the Snork back-story , a few ventured to the surface ( which the Snorks believe is `` outer space '' ) in 1643 , and watched a Royal Navy ship being attacked by pirates .