I've just received a Sailing Instruction with the following course
instruction

10.1 The diagram below shows the approximate course configuration. Mark
1 shall be to windward of Marks 3A/3B. Mark 2 shall be laid as a
distance mark and shall be approximately 50 m from Mark 1. Marks 3A/3B
shall be approximately 50m to windward of the Start/Finish Line. The
approximate Magnetic Compass Bearing from the Start/Finish Line to Mark
1 may be displayed on the Race Committee Vessel.



MARK 1
MARK 2










MARK 3A MARK
3B




Start/Finish Line End Buoy
RC Vessel


10.2 The Course descriptions are :
? One Lap - indicated by Numeral Pennant 1.
START - 1 - 2 - FINISH
? Two Laps - indicated by Numeral Pennant 2.
START - 1 - 2 - 3A/3B - 1 - 2 - FINISH
? Three Laps - indicated by Numeral Pennant 3.
START - 1 - 2 - 3A/3B - 1 - 2 - 3A/3B - 1 - 2 - FINISH
? Four Laps - indicated by Numeral Pennant 4.
START - 1 - 2 - 3A/3B - 1 - 2 - 3A/3B - 1 - 2 - 3A/3B - 1 - 2 -
FINISH

10.3 Marks 1 and 2 shall be left to PORT.

10.4 Marks 3A/3B are a gate. When a boat passes through the gate it
must either leave Mark 3A to STARBOARD or Mark 3B to PORT.


I can read and understand the course OK, what I need some help with is,
all things being equal, with no interboat considerations, how to go
about making the choice between the port and starboard roundings out of
the leeward gate.

I can see that if the wind has come left of the course, then the
Starboard rounding round Mark 3A seems to be favoured because it will
give a long gaining tack to the windward mark, and that if the wind has
come right, the port rounding round Mark 3B will be favoured with the
added advantage that the gaining board will be on starboard.

What are the considerations in choosing which rounding to take out of
the gate?

John