NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bob Crawley
Date: 2025 May 25, 23:16 -0700
A bit off topic, I know, but there are several nautical historians here who may be able to help. I'm trying to derive the value of Mean High Water Springs (MHWS) from an 1845 Survey. The values I have are for Rise and Fall (in feet, of course) at Full and Change. I'm familiar with the use of Full and Change of the Moon for tidal calculations. It seems to me that Rise and Fall is the same as tidal range, as it is the change of the Moon, then it should mean the Spring tide and be the same as MHWS range. I'm not concerned about the Chart Datum, just the range.
I've always wondered about whether F&C is the same as Spring tide, since the Spring usually occurs a day or two after the Full/New Moon.
Any observations, please?
Hopefully, it's OK to post this even though it's not really navigation.
Thanks
BobC
52N1E
