Tide Terminology - Everything you need to know

We find ourselves often talking in terminology that doesn't always makes sense if you haven't heard the phrase. When it comes to tides there is a lot to know and tidal terminology encompasses a variety of words and phrases to describe the movement of tides and related phenomena. Here's a comprehensive list of tidal terms! We hope this helps improve your fishing experience and knowledge! 

Tidal Movements:

  • Ebb Tide: The outgoing or falling tide, when the water level is receding.

  • Flood Tide: The incoming or rising tide, when the water level is increasing.

  • Tidal Current: The horizontal movement of water associated with the rising and falling of tides. It includes ebb currents and flood currents.

  • Ebb Current: The tidal current that moves seaward, away from the shore, during the ebb tide.

  • Flood Current: The tidal current that moves landward, toward the shore, during the flood tide.

Tidal Phases:

  • High Tide: The point in the tidal cycle when the water level reaches its maximum height at a particular location. (H) used frequently on Tide Charts.

  • Low Tide: The point in the tidal cycle when the water level reaches its minimum height at a particular location. (L) used frequently on Tide Charts.

  • Tidal Range: The difference in water level between high tide and low tide.

  • Spring Tide: Occurs during the full moon and new moon phases, resulting in higher high tides and lower low tides due to the combined gravitational pull of the moon and the sun. A "big swing" tide, also known as a "spring tide," is a tidal condition where the difference between high tide and low tide is relatively large. Spring tides occur during the full moon and new moon phases when the gravitational pull of the moon and the sun align. This alignment results in higher high tides and lower low tides, creating a larger tidal range.

  • Neap Tide: Occurs during the first and third quarter moon phases when the moon and the sun's gravitational pull is at right angles, leading to lower high tides and higher low tides. A "small swing" tide, also known as a "neap tide," is a tidal condition where the difference between high tide and low tide is relatively small. Neap tides occur during the first and third quarter moon phases when the gravitational pull of the moon and the sun is at a right angle to each other. Neap tides produce lower high tides and higher low tides, resulting in a smaller tidal range.

Tidal Characteristics:

  • Tidal Bore: A sudden and strong surge of water that rushes up a river or narrow bay, caused by the incoming tide meeting a strong river current.

  • Tide Tables: Published data providing information on predicted tide times, tidal heights, and tidal currents for specific locations, essential for planning activities like fishing and boating. (As seen in image above.)

  • Tide Gauge: An instrument used to measure and record water levels, often located at ports and coastal areas for monitoring tides.

Tidal Datum:

  • Tidal Datum: A reference point used for measuring tidal heights and tidal currents. Common tidal datums include Mean High Water (MHW), Mean Low Water (MLW), and Mean Sea Level (MSL).

Tidal Cycles:

  • Tidal Cycle: A complete tidal cycle, typically involving two high tides and two low tides in a 24-hour period.

  • Slack Tide: The short period between the ebb and flood currents when the water is relatively still and changes direction.

Tidal Patterns:

  • Semi-diurnal Tides: Tides with two high tides and two low tides of nearly equal height each day, which is common in many coastal regions.

  • Diurnal Tides: Tides with only one high tide and one low tide each day, which occur in some areas.

  • Mixed Tides: Tides with a combination of both diurnal and semi-diurnal tidal patterns, resulting in varying tidal heights.

  • King Tide: A "king tide" is an informal term used to describe the highest tides that occur during the year. These exceptional tides result from the gravitational influence of the moon and the sun, and they often lead to temporary coastal flooding, providing a glimpse of the potential impact of rising sea levels on coastal communities. King tides are a crucial reference point for understanding and planning for the effects of climate change on coastal areas. If you haven't seen a king tide event in Ilwaco it is a must! 

Understanding these tidal terms is crucial for a wide range of activities. At Spawn we use them in relation to fishing but this is great information to know from navigation and fishing to beach combing and coastal planning. Tidal conditions can significantly impact safety and success! Shop Spawn and comes see us!

 

*image from tides.net

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