A Ro-Ro Ship Ro/Ro Ship or RoRo Ship allows wheeled cargo to be driven on board rather than loaded by crane. This could be a cargo of new cars or vans but Ro-Ro can also refer to passenger ships such as ferries and military transporters which carry tanks. Ro-ro is short for roll on / roll off.

A RoPax ferry transports vehicles (roll-on roll-off) as well as passengers (pax).

A Roll-On / Roll-Off Ship also called a Ro-Ro Ro/Ro or RoRo Ship allows wheeled cargo to be driven on board rather than loaded by crane. This could be a cargo of new cars or vans but Ro-Ro can also refer to passenger ships such as ferries and military transporters which carry tanks. 

A Reefer Ship is a Container Ship that has refrigeration and is used for transporting frozen foods such meat fish and ice cream as well as produce that news to be kept chilled such as fruit and dairy products.

A Reefer Box is an insulated shipping container designed to carry cargo such as fresh food produce that needs to be temperature controlled.

Return Cargo is a term used to describe it when a ship returns with additional cargo to the port where the initial cargo was loaded.

Rolling Cargo is cargo with wheels - such as cars trucks trailers buses or even tanks - which can be driven on to a ship. (See Roro ship.)

Running Aground or grounding is when a ship touches or hits the ground in a shallow part of the sea a river lake canal or other waterway and gets stuck.