The South Bay Charter's Handbook- When To Plan A Cruise

When to Plan a Cruise
During most of the season, you can count on the afternoon northwest wind in the South Bay and wind coming more from the west in the North Bay. The other significant variable is the tidal current. The ideal plan is to have the current going with you in all directions but that's not always possible. If you can just plan to have the current in your favor at the critical times, you'll have a great advantage. There are places in the Bay where the current is stronger than elsewhere. These places can be seen in the current charts of San Francisco Bay. There are also days every month when the current is stronger than on other days. When the tides are the most extreme, it's called "spring tides". The least extreme tides are called "neap tides". The tidal current is of course strongest during the spring tides. Tide and current tables are available on the web and in booklet form at Spinnaker and many other marine facilities.
If possible, plan a cruise so the current is favorable or at least not too unfavorable when you're going to be passing through areas where the current is strongest. The tides and currents tend to be in opposite phase every week. If it turns out the current is going to be unfavorable for your passage one week; you can expect it to be favorable the following week. That's assuming you plan for approximately the same departure time. Modern cruising often involves a lot of motoring. Accept the necessity of motoring, especially if your going to start early in the morning before the wind comes up.