San Francisco Tides

Time Event Value Units
12:26 am Low Tide 2.91 ft
02:36 am Slack
04:18 am Max Flood 0.8 kt
05:22 am High Tide 4.32 ft
06:12 am Slack
10:42 am Max Ebb -2.5 kt
12:25 pm Low Tide 0.26 ft
03:06 pm Slack
05:48 pm Max Flood 1.9 kt
07:59 pm High Tide 4.7 ft
09:00 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?