Why naval historians still need archive research trips

Why are research trips still necessary when many archival sources are online?

Because much remains undigitized and even available scans can omit the surrounding material needed to interpret a source correctly.

Many primary sources have never been digitized, and digitized collections may reproduce only part of a file. Scanning decisions can crop annotations, reverse sides, enclosures, or adjacent documents that explain why the main item was created. A researcher working only from an online image may therefore miss context that becomes obvious when handling the complete archival folder. The answer makes travel part of evidence control rather than academic ritual: visiting the archive allows the historian to check completeness and follow connections that a catalog or selected scan cannot expose.