Difference Between Chart Datum And Mean Sea Level
Introduction
Whether you are a sailor or a coastal engineer, understanding the difference between chart datum and mean sea level is crucial. These two concepts are often used interchangeably, but they are not the same thing. In this article, we will explore the differences between chart datum and mean sea level.
What is Chart Datum?
Chart datum is a reference level used to measure depths and heights in the water. It is the level below which all depths shown on a nautical chart are measured. Chart datum is usually set at a level that is below the lowest tide level expected at a given location. This ensures that the depths shown on the chart are always conservative and safe for navigation.
What is Mean Sea Level?
Mean sea level is the average height of the sea surface over a long period of time. It is calculated by taking measurements of the sea surface over a period of years and averaging them out. Mean sea level is used as a reference level for a variety of purposes, including the study of climate change and the planning of coastal infrastructure.
How are Chart Datum and Mean Sea Level Related?
Chart datum and mean sea level are related because they are both used as reference levels. However, they are not the same thing. Chart datum is a fixed level that is used as a reference for measuring depths and heights in the water. Mean sea level, on the other hand, is a constantly changing level that is used as a reference for a variety of purposes, including the study of climate change and the planning of coastal infrastructure.
Why is Understanding the Difference Between Chart Datum and Mean Sea Level Important?
Understanding the difference between chart datum and mean sea level is important for a number of reasons. For sailors, it is important to understand chart datum so that they can navigate safely. For coastal engineers, it is important to understand mean sea level so that they can plan coastal infrastructure that is resilient to changing sea levels due to climate change.
Conclusion
In conclusion, chart datum and mean sea level are two different concepts that are often used interchangeably. Chart datum is a fixed level used as a reference for measuring depths and heights in the water, while mean sea level is a constantly changing level used as a reference for a variety of purposes. Understanding the difference between these two concepts is important for sailors, coastal engineers, and anyone else who works in or around the water.