Yes, course CHART 16 is confusing at first. Page 1 gives a little map of the marks in Santa Monica Bay and lists the courses. Page 2 provides the approximate bearing and distance between marks, and their approximate latitude and longitude. When using course Chart 16, the starting area will be in the vicinity of S mark.
The race marks, with the exception of marks Q, U and R, are fixed marks and are yellow spar buoys. Basically they look like a yellow pole. They can be hard to spot, and as you can see from the map there are several of them out there!
You will know which course you will race at your start. At the five-minute warning for your start, your class flag is displayed. Usually the course flags are displayed at the five-minute warning as well, however the race committee actually has until the four-minute signal to post the course flag. The course is indicated by numeral pennants AND a letter pennant. The numeral pennants let you know the course number, the letter pennant lets you know the direction of the weather mark.
Say that at your start you see a “D” flag, and a “two” flag over a “three” flag (if you don’t know your flags, get a cheat sheet from West Marine or find them online HERE). This means you are racing course 23 in the direction of D mark. D mark is bearing 235 degrees from S mark (the start will be near S mark). Course 23 is Start-W-S-W-Finish. After starting go the windward mark (W), which in this case is D, round D (to port as usual) and go to S mark. Round S to port and go back to the windward mark (W), which is D, round D to port and then head home to the finish.
If the windward mark is indicated by WW (as in course 30, then in this case you would go to mark DD (if the letter flag at the start were E, with a WW windward mark you would go to mark EE).
If the windward mark is indicated by U, as in course 20, then you will go to an inflatable mark set by the race committee (usually a tetrahedron). U mark will be midway between S mark and the mark indicated by the letter pennant on the race committee.
Note that courses 1-15 have an upwind finish, courses 20-34 have a downwind finish.
Consider course 6: Start-W-S-W-L-F and let’s say the race committee displayed letter pennant E with this course. All marks will be left to port. After the start you would go to the windward mark (W), which is E (direction 260 degrees from S), round E, go downwind to round S, go back upwind to round E, and now go downwind to the leeward mark, called L in the course. You need to look at the map to see what the reciprocal leeward mark is for E – it is the mark that is 180 degrees from E, you’ll see that is mark J. You’ll round J (bearing 84 degrees from E) and then head upwind to finish.
If you find this incredibly confusing, make sure you find someone to help you understand it before race day as the race committee can’t help you then! You’ll probably be surprised by how fast you pick it all up.