As I approach 60, I suggest you think through how you want to use the piece. Daily driver? Dress watch? Something for adventures? Something special (wild card)? I think that will help narrow the field. My choices for each would be: Speedy (daily driver), Cartier Tank (dress), Seamaster GMT (adventure watch), and Dornbluth and Sohn Kalbe (wild card). Lot's of good choices in that price range!
Hi-- basically, the one that is tide only watch (Chronmarine) uses a manual movement to track high and low tides for a given area for one day. You look that up to set it for you area. I think one is from 1970. The other one, tracks the tide for one cycle of the moon (about 29 days). You set it for the moon phase in your area. Tidal swings are influenced by the moon phase and the biggest swings are around the full and new moons. The Heuer Solunar was designed for hunters and fisherman. Solunar theory is the idea that the moon phase, coupled with the time of the day, influences the when animals and fish are most active. There are still a few variations out there in modern watches that do this (Casio has a solar fishing watch; Oris's Dat Watt special edition Aquis does the tide by moon tracking; Ball has two versions of a tide watch, etc.).
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