Mooring Definitions..

[guernseyman]

If it is "awash" then some of it is above water if only between waves so there is no way anything could float over it.

The range of tides varies from springs to neaps, but 1/2 tide is not always the same depth above datum. Check your tide tables & plot the mid tide point over a series of tides, it will not be a flat straight line, it fluctuates. Wave heights also affect what is awash & what isn't, these terms are VERY imprecise simply because nature is not that predictable.

You don't seem to understand the term "awash". Not do you understand half-tide.
Maybe you are in a peculiar location where half-tide height varies. It doesn't in most places. I'm prepared to believe that the height of half-tide varies by a decimetre: it's hard to tell when tide tables give tide heights only to the nearest decimetre. And they are only predictions, not gospel.
Most of us know that waves alter water depth. No need to tell the world, not least because there are other factors that influence the actual depth.
Unpredictability is not an excuse for giving up; one calculates the predictable elements, and estimates the less predictable ones.

 

[chewi]

You don't seem to understand the term "awash". Not do you understand half-tide.
Maybe you are in a peculiar location where half-tide height varies. It doesn't in most places. I'm prepared to believe that the height of half-tide varies by a decimetre: it's hard to tell when tide tables give tide heights only to the nearest decimetre. And they are only predictions, not gospel.
Most of us know that waves alter water depth. No need to tell the world, not least because there are other factors that influence the actual depth.
Unpredictability is not an excuse for giving up; one calculates the predictable elements, and estimates the less predictable ones.

I wonder whether "halftide height" would be the midpoint between high and low? or would it be the height halfway through the cycle?, and then at springs or neaps?

All 4 are different at Poole, and prob also in the solent, perhaps (as you say) not by much more than a decimetre, but if the tidal range is as low as it is in Poole, that decimetre can take a long time to rise, so it'd make a big difference to how useful a mooring is for a given draft.

All told the terms are undefined and ripe for misunderstanding.

 

[JumbleDuck]

All told the terms are undefined and ripe for misunderstanding.

I suspect that to have any meaning the terms have to have local meaning; what someone in Poole means by "quarter tide" needn't be what someone on the Solway means by "quarter tide" as long as the local definitions are known.

I count myself lucky to sail mainly one the west coast of Scotland, where the tide sloshes around a bit, and sometimes quite a lot, but doesn't really go up and down much.