Seiko 6F24 Tidal Chronometer

I bought this watch in Nakorn Ratchasima (Khorat) for my Father-in-Law

a couple of years ago (maybe 1996). My father-in-law is a passionate fisherman and skipper and I thought this might be a useful gift. Last year, he returned the watch to me and said, it was too complicated to use and not really accurate enough to predict the high and low tides and most of all, he could not read the small numbers in the dial.
Of course I was quite happy to get this really special Seiko, a great addition to the specialty department.

This is how the Tidal Read-Out works

1. Turn the date ring (controlled by the purely mechanical crown at 9 o'clock) to the high tide time of your current location

2. Turn the bezel's high tide mark to the time of the high tide of your current location

3. With the help of the 2 and 4 hours mark on the bezel, you can roughly determine the hours before and after high tide