There are several types of ship tankers used to transport liquid cargo:

1. Crude oil tankers: These are the largest type of tanker and are used to transport unrefined crude oil from oil-producing regions to refineries around the world.

2. Product tankers: These are smaller tankers used to transport refined petroleum products such as gasoline, diesel, and jet fuel.

3. Chemical tankers: These are specialized tankers designed to transport a wide range of liquid chemicals, including acids, bases, and industrial solvents.

4. LNG carriers: These are tankers designed to transport liquefied natural gas (LNG), which is a form of natural gas that has been cooled to a liquid state for easier transport.

5. LPG carriers: These are tankers designed to transport liquefied petroleum gas (LPG), which includes propane and butane.

6. Asphalt/bitumen tankers: These are tankers designed to transport viscous liquids such as asphalt and bitumen, which are commonly used in road construction.

7. Vegetable oil tankers: These are tankers designed to transport vegetable oils, such as palm oil and soybean oil, which are used in food products and as biofuels.

Each type of tanker is designed to transport specific types of liquid cargo, and they vary in size, shape, and capacity depending on the type of cargo they are intended to carry.