fm
Fm (symbol) means Abbreviation for "fathoms," a unit used to measure water depth. Example: “The chart marked the channel at 12 fm.”
How to use fm
Learner’s notesIn plain EnglishA short way of writing "fathoms" on nautical charts and depth readings.
Don't confuse this abbreviation with FM the radio broadcasting format — context (nautical charts vs radio dials) makes it clear which is meant.
Fill the gap
Can you complete this real example?
The chart marked the channel at 12 _____.
Frequently asked questions
What does “fm” mean?
The word “fm” means abbreviation for "fathoms," a unit used to measure water depth. In plain terms, a short way of writing "fathoms" on nautical charts and depth readings.
How do you use “fm” in a sentence?
Here is “fm” used in a sentence: “The chart marked the channel at 12 fm.”
What part of speech is “fm”?
“Fm” is a symbol.
Is “fm” a common word?
“Fm” is a fairly common word in modern English.
What is the difference between fm and FM?
In nautical use, the lowercase abbreviation fm stands for fathoms, the unit used to measure water depth. Capital FM most often refers to frequency modulation, the radio broadcasting method, which is a completely unrelated term. Context and capitalization usually make clear which one is meant.
How much depth does fm represent on a nautical chart?
The abbreviation fm stands for fathoms, and one fathom equals six feet (about 1.83 metres). So a chart marking of 10 fm indicates a water depth of sixty feet.
When should you use fm instead of ft?
Use fm when recording water depth in fathoms, the traditional maritime unit, and ft when measuring in feet. Fathoms are used almost exclusively for depth at sea, so fm belongs on nautical charts and in sailing contexts rather than in general measurement.
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