Study of worm (barnacles teredos), the animals are in salt-water or brackish water in species of polychaetes (shipworms) always damage the ship. It would be necessary to bring the ship to the beam for check, clean, patch and change the steel of the hull below the water line. Mostly the small creatures its effect to propeller and hull is worm (barnacles), which has the different shape and characteristic according to the geography. When worm stick to the hull below the water line. The speed of boat will be down because increasing of the friction or resistance of the steel hull. From observations the ship in dry dock for hull cleaning the steel surface below the water line riddled with jag because of corrosion from electrical or salinity of the sea. That makes worm (eggs or larvae) can stick and spread easily.
The study revealed that. So the researchers made "Tool for small worm removal under the water line" use it when the ship stays in harbor for a long time. It reduces cost of the maintenance and the environmental problem as well.