When you are sailing towards a nearby destination, and the winds are light and variable, always choose the tack that has you closest to your destination. In this case, we are sailing from Horta to Angra do Heroismo. The winds have been from all directions and all intensities. Overnight it has varied from 0 to 18 knots, and from the North, South, and East!
We are we're on a beat with NE winds as we were approaching Terciera when the winds became more easterly. We could continue on this same tack heading SE for about 10nm and then tack over and head North. This would work in theory, but it requires the winds to remain from their same direction!
What if you spend 3 hours lining up the perfect approach and then the winds shift again? The safe thing to do is tack frequently and often, keeping your yacht aimed in the general direction of "being closest". Yes, short tacks are inefficient, especially on a full keel yacht, but it is better to be "almost there" when the wind shifts than to be "really far away."