Many folks reading this are seasoned SCUBA divers, or recreational mariners & have already been exposed to ideas immediately below; perhaps more accurately & in much greater detail. But, it's become obvious that not everybody in our group has that background--until now. It's my hope this blab can stand as a primer, for anyone in the club who's confused by "Spring tides", "Neap tides", low-water peaks (A.N.s), etc. & wonders why we pay attention to that stuff...