"It can tell us the exact tide level, even in real time."
Well it's stretching it a bit to call it "exact." It gives a prediction based on NOAA's multiharmonic model of tidal fluctuations. The "exact" level on any given day can be influenced by weather and other variable conditions. A quick look at NOAA's composite plots, which show the residuals between predicted and actual tide levels, shows that the predicated values can vary by a couple feet at times. Today, for instance, the actual levels are running a couple feet high in the northeast US due to the weather events happening out in the ocean.
Well it's stretching it a bit to call it "exact." It gives a prediction based on NOAA's multiharmonic model of tidal fluctuations. The "exact" level on any given day can be influenced by weather and other variable conditions. A quick look at NOAA's composite plots, which show the residuals between predicted and actual tide levels, shows that the predicated values can vary by a couple feet at times. Today, for instance, the actual levels are running a couple feet high in the northeast US due to the weather events happening out in the ocean.