Larkspur works best on a Southwest in mid to late summer. When the fog is over Crissy, shutting it down, it can be good at Larkspur. Look for a high bank of fog hanging over Mill Valley and the flanks of Mt. Tam. When it comes up, it can be good from early afternnoon (sometimes as early as 11:00 AM) to 6 or 7. Typically it will blow for 3 or 4 days in a row, sometimes up to 10 days on a good stretch. On a zero or lower tide, not much sailing area is available unless you want ot sail the channel out past Pt. San Quentin.
Sailors should be aware of Ferries in the channel arriving and departing from the nearby terminal.