I like the solution put forward by Phil. One tweak might be to allocate the gate berth to the boat finishing (say) third in the previous race. This approach makes the rotation of fixed positions slightly more complicated but avoids the potential of intimidating novice sailors from having to operate as gate boat. Also, in some clubs where there might be a significant boat speed difference between the top and other sailors you would also avoid the probability of the faster boats taking the gate really early, overtaking the gate boat and going “loose cover” on the fleet. Apologies if I have spent too long indoors - I may be over thinking this !