Sometimes, divers encounter fish moving inside the wreck. If the fish is a venomous one, it is better not to approach it because it can attack divers. Do not force to enter rooms, such as machinery room, or navigation that are blocked by pillars, sling, or fallen furniture.
Some shipwrecks have explosive materials such as bombs and torpedoes. Don't try to turn or remove them. They can explode and ruin the whole ship's structure.
After diving, you can contact the shipping archives of the local government if the ship was of the territory. If the shipwreck was from other country. You can contact the country, or the ship owner to find out detailed stories about the wreck.