Marine Vocabulary

Leeway

The sideways drift of a vessel downwind of its intended course, caused by the aerodynamic drag of the wind pushing against the ship's superstructure (everything above the waterline).

Heading

The direction the ship’s bow is pointing.

Course Through the Water (CTW)

The actual path the vessel tracks through the water after accounting for the wind's push.

Narrow Channel

A restricted, narrow navigable waterway—such as a river, strait, harbor entrance, or dredged fairway—where the safe passage of vessels is physically constrained by the surrounding shallow water, underwater hazards, or landmasses.

Estuaries

A partially enclosed, coastal body of water where freshwater from rivers or streams meets and mixes with salty water from the open ocean. It serves as a transition zone between river environments and maritime environments, characterized by water that is brackish (semi-salty) and heavily influenced by the rise and fall of the tides.

Harbor

A sheltered body of water where ships, boats, and barges can seek refuge from turbulent open-sea weather, anchor safely, or dock alongside piers and wharves to conduct commercial operations like loading, unloading, and maintenance. Harbors can be natural (formed by protective geographical features like bays or inlets) or artificial (constructed using man-made breakwaters, jetties, and deliberate dredging).

Contour

In the maritime industry, contour almost always refers to Depth Contours (also called bathymetric lines) on nautical charts. When navigating with an ECDIS (Electronic Chart Display and Information System), managing your contours is one of the most critical safety tasks an officer of the watch performs.