They're a lot of great descriptions of the Elie Chainwalk (see https://www.ukclimbing.com/forums/hill_talk/elie_chain_walk-546218?), but they're all marred by not-so-useful explanations of the tidal restrictions. Many authors mention that it's not possible throughout a high-water window 2 hours either side of high tide. This may be because, despite being a 'seafaring nation' , most people don't understand tides (and I'm sorry to say Dan's '2 hours either side of low-water' seems exceptionally over-cautious).
The important thing is: there are (generally) two high tides and two low tides per day, each roughly 12 hours apart and the height of these change from day to day over a two-week cycle.
A good resource for seeing this visualised is: https://tides.willyweather.co.uk/ta/fife/earlsferry.html
We've found that tide height needs to be below roughly 4.2m to keep your feet dry on the Elie Chainwalk - sometimes this means you can complete the walk at high water (during Neap tides), and sometimes it's only possible 4 hours either side of low water (during Spring tides).
The key thing is that you leave sufficient time when you set off - if you're a nimble and competent scrambler (and you're not stopping to explore or take pictures, or are held up by slower parties!) it can be completed in 15 minutes. If you want that added frisson of danger, with the sea lapping (or heaving) below you, then you'll want to push yourself closer to 4.2m.
All of the discussion about tides heights has to be moderated by consideration of the sea conditions - if the waves are big you could still be swept off or just get wet feet even when the tide height is below 4m.
