Submarine

You and your team have adventured on a journey in search of a mysterious, abandoned submarine. Which the legend says, comes to the same spot of the water once a year. They say the captain, which was mad, took steam punk inventions and incorporated them into the mysterious submarine. They say the submarine didn’t use any fuel, and moved like a living creature. In the captains last records there was something about the submarine having a heartbeat, and that begun to beat slower and slower.