I have a watch that asks me for the “Luni-Tidal Interval” at a particular location. What is it, and where can I obtain it?
The term “Luni-Tidal Interval” is an archaic term, and in place of it we now use the term “Mean High Water Interval” (MHWI). This term refers to the mean time interval between the Moon’s transit (upper or lower) over the Greenwich Meridian and the time of the next High Water at the place concerned. Thus the Mean High Water Interval refers to the average of all such High Water Intervals, for all transits of the Moon, over a particular period of time. You may wish to consult Admiralty Co-Tidal Chart 5058, “Co-Tidal & Co-Range Lines: British Isles and Adjacent Waters”. This chart displays Co-Tidal lines drawn through points of equal Mean High Water Interval, and Co-Range lines drawn through points of equal Mean Spring Range. Full instructions on how to use the chart are published on it.
Related Questions
- I have a watch that asks me for the "Luni-Tidal Interval" at a particular location. What is it, and where can I obtain it?
- How can I obtain an image/animation for a specific date/time, in a particular format or for a specific location?
- How do I obtain a differently formatted file to satisfy a PACS vendors particular requirements?
