Here you can see the Navionics tidal currents with times displayed at the peaks and troughs. Are these gmt , bst or cet? The tide height graph tells me ...
... but the tidal current isn't very clear.
The device is set to BST because it kept resetting itself when I changed to CET .
FYI... i reached out to Navionics and they said times are based on the location the app senses you are in. The device time does not have a bearing on how Navionics works.