Despite the anchor being a vital part of the function of the ship, it is not visible at all, even when lowered.
The Barge of the Damned, where players go when they die, bears resemblence to Davy Jones and his Flying Dutchmen ship.
The four songs you can play on your instruments are "Bosun Bill", "Ride of the Valkyries", "Grog Mayles", and "Becalmed"
On one of the islands a skeleton eating bananas is seen sitting agaisnt a rock that bears the name "Griffin". This is a reference to a reviewer at the website 'Polygon' who attempted to eat a banana with the peel on and top first, which is how it appears the player eats bananas in game.
Seen in some of the promotional images, the Kraken is a real entity in the game. It can be encountered anywhere at random, but typically spawns in deeper waters. The Kraken can also appear suddenly, rapidly push or pull your ship, and then disappear under the waves. It has 8 tentacles and can be fought off if it attacks your ship.