Treasure under the Sea

"Treasure under the Sea" is the 9th episode. "Treasure under the Sea" features naval flag signalling.

Plot
Lots of treasure is found in a sunken ship. A submarine is stolen. Sherlock Hound is working on a car and the authorities ask him for help or something. Some scenes from the intro are seen in the non-intro part of this episode. Prof. Moriarty is in a submarine and engages in naval warfare with a battleship. Moriarty tries to get the treasure. Sherlock Hound flies around in an airship and spots Moriarty. The airship gets very close to the submarine and Moriarty and his lackeys try shooting it with their guns but fail. Another ship gets torpedoed and sinks. Captain Raythunder (might not be spelled right) has Napoleon's treasure then fights some guys. The submarine picks up bags of treasure and puts it in itself. Moriarty celebrates what he thinks is the death of Sherlock Hound, but Sherlock Hound rides a torpedo to above the water, destroying the submarine in the process. Captain Raythunder meets his brother and one brother wants to keep the treasure while the other wants to give it to a museum.

Trivia
The title case of the name of this episode, as posted on YouTube, is inconsistent; it is "Treasure under the Sea", but it properly should be "Treasure Under the Sea".