5 Boating Terms You May Be Using Incorrectly

It's not just newbies who find boating terms confusing. Even experienced boaters, who've mastered basic boating terminology, can slip up on the subtle difference between words. So, how well do you know your nautical nomenclature? Read on for a list of commonly confused terms.

Line versus rope: As a beginner, you may have learned that every piece of onboard cordage should be referred to as line, not rope. However, there's an important caveat to this rule. The primary difference between rope and line is its function. A line has a job to do (e.g., main sheet, docking line), whereas a rope has no job or immediate purpose. You likely have some spare rope coiled up in a lazarette or locker.

Deviation versus variation: This is one of the top incorrectly answered questions on boating exams. Variation is caused by the misalignment of magnetic lines of force with the meridians of longitude. Deviation, on the other hand, is unique to a vessel. It's caused by the magnetic properties of batteries, large metal objects, and electronics in the immediate vicinity of the ship's compass. Both compass deviation and variation must be accounted for.

Course versus heading: A heading is the compass direction a vessel's bow is pointing at a single point in time. However, it may not necessarily be the vessel's intended direction of travel, which is known as the vessel's course. Imagine trying to hold a course of 180 degrees at sea. The heading is likely changing — your compass reading may be 185, 182, 177 degrees — as the boat is affected by the wind and waves. So, while a vessel's heading and course can be the same, most of the time they aren't.

Lee, leeward, leeway: Lee refers to the side of an object that is sheltered from the wind. To be "in the lee" is to be on the protected side of an object, for instance, in the lee of a point. A "lee shore" however, is to be avoided. The shore on the lee side of a vessel is considered more dangerous because the wind can drive the vessel onto the shore in inclement weather or if the vessel loses propulsion. Leeward means toward the lee (i.e., the opposite of windward.) Leeway is the leeward drift of a boat due to the wind.

Sea versus swell: Swell is wind waves that travel beyond the area in with they were generated. For instance, a storm may generate swell that travels thousands of miles across an ocean. In contrast, the term sea is a description of wind waves that are locally generated. As waves travel away from the area in which they are formed, the shorter ones die out and their surviving waves become more regular, longer period and have flatter crests.