Assertion: ocean's depth | /r/HasProperty | relative
Facets:
value: to a "chart datum"
type: OTHER
Source sentences:
text: These depths are relative to a "chart datum", which is typically the water level at the lowest possible astronomical tide (although other datums are commonly used, especially historically, and tides may be lower or higher for meteorological reasons) and are therefore the minimum possible water depth during the tidal cycle.