A flood or flood current in sailing is the incoming tidal current that moves toward the shore, into a bay, or up a river, occurring as the water level rises from low tide to high tide. It is the opposite of an ebb current (outgoing) and is crucial for planning navigation speed and direction.

Key Aspects of Flood/Flow Tides:
Direction: Flows from the sea towards inland or coastal areas.

Timing: Lasts from low water to the succeeding high water, although the current may continue to flow for a short period after high water.

Impact: A "flood" often boosts a boat’s speed when traveling inland (with the current) but reduces it when heading out to sea.

Synonyms/Context: Often used interchangeably with "flood tide" or "flowing" water, particularly in estuaries and tidal rivers.