Not sure if people are aware of this, but I found it useful...
If you are making charts in estuaries or anywhere tidal, there is a good source of 'historical' tidal data you can use to post process. As you are probably aware, wxtide etc use predictions for tidal values. These can be affected by atmospheric pressure, rainfall etc. If you want to apply exact tidal values that occurred during your data collection period, you used to have to set up your own tidal monitoring station. Now, the environment agency has set up many recording stations around the uk for flood defence warnings - which is useful for us as we can use the data which is freely available on 3rd party web sites such as gaugemap.co.uk . Note though that the data is usually referenced to MSL - so if you are using LAT you will have to convert (you can get the conversion value from ukho). At the moment you have to take the values off the graph and make a txt file to import into RM. Anyone know if there's a website to download csv files?
Even if you don't import the data to RM and use a 'user station' in wxtide, it's a good source of info to see if your user station provided accurate predictions and if not, slightly tweak the user tide values to improve the data.