Same here; still looking for an explanation. Also, I remember seeing a map showing the daily number of tides and it's not the same everywhere; some place only have one tide each day, others have 2 but other places have 4. It can also be different along the same coast, so I have no idea how the tides work. I cannot find that map so if anybody know what I'm talking about, please share; or if I remembered wrong, please correct me.