San Francisco Tides

Time Event Value Units
02:12 am Low Tide 0.88 ft
05:07 am Slack
07:59 am Max Flood 1.4 kt
09:52 am High Tide 3.91 ft
10:35 am Slack
12:54 pm Max Ebb -1.1 kt
01:19 pm Low Tide 3.48 ft
03:33 pm Slack
05:55 pm Max Flood 0.9 kt
07:29 pm High Tide 5.71 ft
07:42 pm Slack
What day is the longest?
Why are there 2 tides per day?
Why doesn't Slack = High/Low Tide?
Why can you ride a flood but not an ebb?