Secret #1: The Flying Dutchman was once a pirate captain back in the 1600's, he and his men purged and prowled the seas uncoevering all sorts of treasure, they were soon known as the greatest and most feared pirates in the world, for having superb and cunning skills at sea and powerful cannon artillery, The Flying Dutchman's name as a pirate captain was Sherman Dutch Redbeard, they ruled the seas from 1623-1651, in 1651 they hit a terrible storm, and the ship wasn't going to make it, the crew was even jumping off the ship, Redbeard climbed onto the mast to try and spot any land, but a lightning bolt struck the top of the mast causing him to fly away and plunge into the ocean, never to be seen again. As a ghost, he has his ghost pirate ship still with him, which is still looted with treasure, and one of the chests was buried near it for safekeeping, but was uncovered by Mr. Krabs, SpongeBob and Patrick in the episode: Arrgh!
The Flying Dutchman was never put to rest because obviously his body was never buried properly in a coffin and then six feet under a Gravestone marked: RedBeard (1600-1651.) October 12th, 1600 is his Birthday. He likes to haunt the seven seas for fun and enjoys scaring sea creatures and people, and he continues to search it to this day for answers and many unknown secrets, areas, and treasure still laying around in the ocean.
A lot of Redbeard's crew are yet to be found in the ocean to this very day as well.
Secret #2: Snellie's mom's name is Rachel Shellstage.
Secret #3: SpongeBob's Grandfather's name is OldHenry RustyPants.