There are several types of electric rust removers that can be used for ships. Here are some of the most common types:

Electrolytic rust removal system: This system uses a small DC current to remove rust from metal surfaces. It involves immersing the metal parts in an electrolytic solution and applying an electrical charge. The rust is attracted to the anode and can be easily removed.

High-frequency electric rust remover: This type of rust remover uses a high-frequency electromagnetic field to remove rust from metal surfaces. It works by creating a rapid vibration that causes the rust to break away from the metal surface.

Pneumatic rust remover: This type of rust remover uses compressed air to blast away rust and other debris from metal surfaces. It's a fast and effective method of rust removal that is commonly used in shipyards.

Portable electric rust remover: This type of rust remover is a handheld device that can be used to remove rust from small areas. It's lightweight and easy to use, making it ideal for small jobs.

The type of electric rust remover that is best for a ship will depend on the size and location of the rusted area, as well as the type of metal that needs to be cleaned. It's important to choose a rust remover that is safe to use on the specific type of metal being treated and to follow the manufacturer's instructions carefully to ensure that the rust is effectively removed without damaging the metal surface.