What is Chart Datum approximately equal to in most UK tidal waters?
Short answer
Lowest Astronomical Tide
Chart Datum is normally close to Lowest Astronomical Tide in UK tidal waters. Soundings are below that datum and predicted tidal heights are above it, so check the chart note before combining them. Revise Tidal Definitions and Datum.
Quick check
What is Chart Datum approximately equal to in most UK tidal waters?