Gang refers to a group of people or a team who work in a port terminal or harbor. Most commonly applied to stevedores / longshoremen / dock workers.

A Gangway is a narrow sloping portable platform used as a passageway so that passengers crew and other personnel can board and disembark a vessel that is moored alongside a dock quay or pier. 

A Gantry Crane (also known as a container crane ship-to-shore crane or container handling gantry crane) is a large overhead track-mounted crane positioned dockside and found at container terminals. It is used for loading and unloading shipping containers from container ships.

A Gas Carrier or Gas Tanker is a vessel that has been specifically designed for the transportation of gasses that have been condensed / liquified. The most commonly transported gasses are Liquefied Petroleum Gas (LPG) which includes propane and butane Liquefied Natural Gas (LNG) which is mainly methane as well as ethylene and ammonia.

Also known as a self-unloading vessel or a self-geared ship a Geared Vessel is a ship that has its own onboard gear - i.e. cranes. This means that the vessel can load and unload cargo including containers without portside assistance thus making the vessel more versatile as it can dock in more ports.

General Cargo consists of both breakbulk cargo (cargo that cannot fit into a standard shipping container and is therefore transported in boxes bags drums crates and barrels etc.) and containerized cargo.

A Gong Buoy is a buoy that is fitted with gongs that are struck by hammers as the buoy moves with the motion of the water.

A Guard Rail is a metal rail that is fitted around a boat to prevent the crew or passengers from falling overboard.