RaceAtlas

Alcatraz Island Tides: Tuesday, April 21, 2026

Tide heights at Alcatraz Island with the flood, ebb and slack schedule at the Golden Gate.

6.3 ft2:29 AM-1.2 ft9:38 AM4.4 ft5:12 PM3.1 ft9:24 PM0 ft2 ft4 ft6 ft12 AM6 AM12 PM6 PM12 AM
High 6.3 ft at 2:29 AM, low -1.2 ft at 9:38 AM. Gate: flood 3.0 kt at 12:31 AM, ebb 1.7 kt at 6:21 AM.
Modelled current at the Golden Gate on a 3.0 kt floodThe Gate at max flood, 3.0 kt
Tide height
TimeHeight
2:29 AMHigh6.3 ft
9:38 AMLow-1.2 ft
5:12 PMHigh4.4 ft
9:24 PMLow3.1 ft
Current · Golden Gate
TimeStateSpeed
12:31 AMmax flood ENE (074°)3.0 kt
3:32 AMslack–
6:21 AMmax ebb SW (235°)1.7 kt
10:47 AMslack–
1:58 PMmax flood ENE (074°)2.7 kt
6:14 PMslack–
8:13 PMmax ebb SW (235°)0.7 kt
10:14 PMslack–

Not for navigation. These are harmonic predictions, not live measurements. Tide heights: station 9414792 (Alcatraz Island). Currents: station SFB1203 (San Francisco Bay Entrance, Golden Gate). · RaceAtlas, the SF Bay current atlas.