Visualizing the tides of San Francisco Bay [Farther, Colder, Rougher]

Just for fun, here is every high and low tide for San Francisco Bay in 2016. Red dots are the high tides; blue dots are the low tides. (click to enlarge)

I found it interesting that the highest low tide of the year is lower than the lowest high tide of the year. There’s a certain narrow range of water levels - about 3.1-3.4 feet - which sees neither high tides nor low tides. Perhaps there’s some obvious reason for this, known to oceanographers, but it was news to me! I’m also curious if the non-overlap of high and low tides is true everywhere?

Any tide gurus out there?