What survey ships do in wartime

What roles do hydrographic and oceanographic survey ships play in war?

They provide the same essential data, particularly for amphibious operations and submarine activity.

Survey vessels retain their core functions in wartime because the information becomes operationally necessary rather than optional. Hydrographic ships chart approaches and help assess areas before amphibious forces move in. Oceanographic work describes the environment in which sensors and submarines must operate. Deep-ocean survey ships therefore support submarine operations while coastal data feeds landing plans and navigation.