Okay, kiddo, have you ever been swimming and had a toy floatie or a pool noodle to help keep you afloat? Well, a paravane is kinda like that for boats, but instead of using it to float, sailors used it to protect their ships during war.
A paravane is a weapon that is used to sweep or search an area in the water for mines. Mines are explosives that can be put in the water to blow up and damage ships. A paravane looks like a big metal fish with fins on the side, just like Dory from Finding Nemo! It's attached to a long metal rope or cable and is pulled behind a ship.
When the ship is moving, the paravane creates a current in the water, like a big fan, which helps it to move forward. As it moves along, the paravane is looking for any mines in the water. If it finds one, the metal cable will hit the mine and cut it, causing it to explode safely away from the ship.
So, think of the paravane as a kind of underwater guard that can help keep ships safe from explosive danger while they're sailing through the water. It's like having your own personal superhero to protect you from bad guys!