Description
Require nonnegative depthFathoms, append the fathom label, and multiply by 1.8288 for depthMeters.
A unit conversion applies a defined or supplied factor to a quantity of the same physical kind. Similar unit names can have different definitions, while fraction scales depend on whether the basis is mass, amount of substance, or volume.
Require nonnegative depthFathoms, append the fathom label, and multiply by 1.8288 for depthMeters.
When to use this tool
Use Fathom Depth Chart Label when you need a transparent conversion under the explicitly stated unit definition and quantity basis.
How to use the tool and how it works
- Enter depthFathoms. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read label, depthMeters. Use the output convention below.
Require nonnegative depthFathoms, append the fathom label, and multiply by 1.8288 for depthMeters.1
The international-foot definition gives one fathom as exactly 1.8288 meters. A fathom based on the former U.S. survey foot has a different conversion; this tool uses the international definition.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| depthFathoms | Nonnegative depth in international fathoms, each exactly 1.8288 meters. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| label | Formatted label for the supplied components under the convention above. | Required. Text; maximum UTF-16 length 8192. |
| depthMeters | Depth in meters under the international fathom definition. | Required. Finite number. |
{
"input": {
"depthFathoms": 10
},
"output": {
"label": "10 fathoms",
"depthMeters": 18.288
}
}Limitations and assumptions
- This uses the international six-foot fathom; historical conventions, chart datum, survey uncertainty, and safe water depth are not verified.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Verify the original definition, quantity type, and measurement uncertainty before combining the result with other data.
References
-
Calculation and input contract: nautical/fathom-depth-chart-label — tool.io
-
U.S. Survey Foot: Revised Unit Conversion Factors — National Institute of Standards and Technology
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