Water Dragon Tales

"Have you ever heard the tale of the Water Dragons?"
"No, sir!"
"Well then, I think it's time for a wonderous story..."

— Classic storytelling introduction in Boparia

The waters of the Dragonhead Sea are filled with strange fish and odd creatures. Due to most sentient races of Renath requiring air to breathe, the oceans of the world have not been explored, and speculation on what lies in the depths is a common topic of conversation for those on its shores. One common belief, supported by many tales, is that strange animals known as Water Dragons live in the deep parts of the Dragonhead Sea, often attacking fishing boats and trade ships that wander too far from the established routes...

From Darkest Depths...

Water Dragons, according to the tales, live deep in the darkest parts of the Dragonhead Sea. While some wonder whether the creatures have ever migrated to other inland seas or the main oceans of Renath, most tales maintain that something in that sea in particular keeps them alive, namely large black jets of hot water from deep within the planet.
The Water Dragons draw strength from the seabed, using hot boiling water on the seafloor to cook their prey. Their scales are a bluish-green and they can release terrible heated jets of water from their mouths. They mostly troll the seafloor when they aren't hunting, using caverns and caves as homes.

...To The Surface

The tales mostly concern what happens when the creatures come to the surface to hunt. While many are content with the sharks and large fish that live in the sea, a large boat of people might be confused for prey and eaten as well. Using a combination of their boiling breath and their thick scales and blubbery hide to quickly cook and eat prey.
Most stories claim to come from survivors of Water Dragon attacks. They will speak about seeing dark shapes in the water, then jumping overboard just before the dragon attacked, swimming away before they could be eaten. They always watch the ship sink as the dragon's large size rips the boat to pieces, and there's always mention of the dragon's water breathing jaws boiling someone alive.
Of course, the major natural scientists of Renath maintain no such creature exists, and no one has successfully slain one beyond a shadow of a doubt. Those who do claim as much are discovered to have killed scaled sharks or blubbery whales, then using the carcasses as manufactured "proof". But some sailors swear by seeing jets of hot water burst from the depths...

Variations

Most tellers of this tale talk about their own experiences as a sailor, claiming to have been attacked at some point by a Water Dragon and using some burn injury that they have as "proof" that the dragon nearly got them. Others talk about the experiences of a parent or grandfather who was a sailor and encountered one of these creatures.
Most have them flee the ensuing battle, desperately trying to be the one who survives to tell the tale. Occasionally, a storyteller says that they attempted to slay the beast, claiming that they stabbed out one of its eyes or cut off a claw or fin. Of course, this only enraged the creature more and they only barely escaped with their life and so on and so forth.
Others say that they cannot return to the sea, as the dragon is still hunting them to finish the job.