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Fathom

Unit of length

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionJul 3, 2026
Entity authoritySource title only
Source-derived summary

A fathom is a unit of length in the imperial and U.S. customary systems equal to 6 feet (1.8288 m), used especially for measuring the depth of water. The fathom is neither an international standard (SI) unit, nor an internationally accepted non-SI unit. Historically, it was the maritime measure of depth in the English-speaking world but, apart from within the US, charts now use metres.

Editorial summary

“Fathom” enters the record as unit of length. Crown Archives preserves that source wording while asking what Fathom, Unit and length can confirm, complicate or overturn.

Editorial reviewA dependable orientation record for establishing vocabulary, names and a first evidence trail. The current 65-word lead offers orientation but no explicit four-digit date, so chronology should not be assumed. The selected authority fields contribute no independent date. Its strongest next move is a source search built around Fathom, Unit and length.
Editorial analysis

Why this record matters

“Fathom” is worth following because a concise public description often conceals a longer documentary argument. Here, Fathom, Unit and length provides the most credible route into that argument.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 3, 2026.

Critical limits

A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Fathom”, its source revision and the description used here.
  2. Expand the search: follow Fathom primary sources, Fathom archive and Fathom research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Fathom”?
  2. What terminology or title could unlock a more precise catalogue search?
  3. Which institution is responsible for the underlying evidence?
Subject index

Search terms from this dossier

Source & attribution

This entry incorporates text from “Fathom” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.