Ironically, something Casio have been struggled with on their fancies G-SHOCK GBX-100 few years ago. Tides were based on database and not cycles and they were always wrong (contrary to the older, more basic, not connected, tides model). I’m a fan of tides G-Shock, I got one and sold it fast unfortunately… maybe the only time Casio disappointed me.
Yeah I own this watch and it is infuriatingly almost accurate for my location, but drifts over the course of the moon cycle. I now just use it as indicative but check other sources if I want the exact high and low tide times. It definitely helps solve the main thing I wanted it for though: glanceable sunrise/set, moon cycle and tide strength (as well as approximate highs and low tide).
The app is kind of clunky and I have had issues with the live GPS tracking of activities but as they're not the main reasons I got it, I don't mind too much.
https://www.watchuseek.com/threads/need-help-gbx-100-tide-gr...