Key Boating Terms

What nautical words mean, and what to do with them.

I grew up around boats, but it wasn’t until I started working for Boating 15 years ago that I heard the term athwartships, as in “Move athwartships and belay that line to the midship cleat.”

Huh? I think my blank stare and statuesque response prompted a quick rephrasing from my senior editor, who issued that command.

“Tie that rope to the middle cleat on the other side of the boat,” he said.


Why do hard-core boaters still insist on speaking an archaic language that nonboaters don’t understand? I don’t know, but the fact is they do. And if you want to be a hard-core boater, or at least hang out with one, it would behoove you to learn the language so you can do the right thing and — more importantly — take decisive action on board. Here then are a few key terms and what the captain using them is trying to tell you.

My editor wanted me to tie off amidships to create a spring line to hold the boat in its slip. A spring line runs forward or aft from the midship cleat — also called the spring cleat — to prevent the boat from moving (“springing”) too far back or forward in its slip. This is especially important with fixed docks in tidal areas, where the spring lines keep the boat centered with the water’s rise and fall.

Attitude (also “Trim”)
When the captain tells you the boat has a bad attitude, he’s referring to how it’s sitting in the water underway. Attitude can be adjusted by changing the angle of trim — moving the bow up or down — either by raising or lowering the engine or by using trim tabs.


A knot is a speed measurement for a nautical mile rather than a statute one. The thing to remember about knots is that one knot is equal to 1.15 miles per hour. Since a knot is also equal to one nautical mile per hour, it plugs into speed-time-distance equations without need of conversion, since one nautical mile equals one minute of latitude.

This refers to the direction of the waves in relation to the boat’s heading. (Going into the waves is being in a head sea; running with the waves, you’re in a following sea; traveling sideways to waves puts you in a beam sea.) “Quartering” refers to waves coming at an acute angle (between 0 and 90 degrees) to the boat’s centerline. Sometimes a head or following sea will be too treacherous and the captain may call to run in a quartering sea, approaching or running with the waves at an off-angle to lessen the blow. (Read Jim Hendricks’ excellent column on the subject at

Boaters trying to find each other ask, “What’s your position?” Your position is a geographical measurement based on where you sit on the intersection of latitudinal and longitudinal lines. This is critical in an emergency situation, when Sea Tow or the Coast Guard will best find you via coordinates on a chart.


Mean Low Water
The average depth of an area at low tide. That’s important to know when cruising areas that may not have enough water to handle your boat’s draft at low tide.