A sailboat can't sail straight into the wind, but though the magic of aerodynamics, the wind rushing around the foil of your sails generates enough lift that you can sail at an angle into the wind. When your destination lies to windward you have to zig zag back and forth, called tacking, making little indirect progress on each tack. As a general rule, most sailboats can sail at about a 45 degree angle to the wind, and each leg of the tack is at a 90 degree angle to the last one. But the actual angle you can sail varies depending on the design of the boat, the trim of the sails, the speed of the wind, and the speed of the boat, And on the ocean, several additional factors affect whether you will be able to make good on 90 degree angle tacks toward your destination, include oblique wave angles and ocean currents. We find that we can never tack as tightly on the open sea as we can on the relatively flat waters of the Hudson River. Passagemaking is further complicated by trying to game expected shifts in wind direction over time and in different places on your route, to maximize the time you spend sailing on a tack closer to your destination. As a general rule, it always seems like you would be doing better on the other tack, but when you tack that turns out not to be true.

With the winds expected to become more southerly as we moved south, it made sense to stay on a starboard tack, making southing, as long as the southwesterly winds held up. Eventually, though, we would hit the Colombia and Ecuador coast, though, with complicating land breezes, fishing traffic, and currents. At the end of my overnight watch Saturday morning, we were still making good progress a little west of due south, and we had a plan to keep sailing starboard tack (wind on the right side of the boat) until we hit 2 degrees latitude, or the wind shifted southerly enough to sail straight for San Cristobal in the Galapagos.

At 0700, Feydris called us on the radio, but they couldn't hear Robin when she answered. They may have been calling to advise they were making their turn west, as the wind had shifted, “heading” us away from our southerly course and more southeast, perpendicular to our southwest course to San C, and directly for the Colombia coast.

A “header” is an adverse wind shift forcing you to sail at a larger angle from your desired course, a “lift” is an advantageous wind shift that allows a tighter angle. A header on one tack is a lift on the opposite tack - so as we were headed on starboard tack,it might have made sense to tack over to port and see if we could now lay a course for San C. But Robin did not want to disturb my sleep with a tack, so we sailed southeast for three more hours until the change of watch at 1000, when we tacked to port, laying a new course straight to our destination.

The tack immediately took us through a line of rain squalls, but on the other side the sun came out and the air was noticeably cooler and drier. A pleasant day of sailing in the sunshine! The wind on the sunny side veered more westerly, though, and we found ourselves creeping to a more westerly, then northwesterly course - to the point that we were going to be driven north of Malpelo Islans. Our track on the chartplotter looked like we had made a wrong turn to the southeast, then turned around and doubled back! By 1530, we tacked again onto starboard tack and could make a course just west of due south, but at 1830 we had been headed again and tacked to avoid a line of rain squalls.

Incidentally, the rain squalls today have been lighter and less violent than the last few days - no lightning or thunder in any of them. Now, at 0200 Sunday, we are sailing port tack, heading just north of due west, and I am thinking we may want to tack again. The wind is always better for the other tack.

Tonight, as last night, we have been followed by white winged birds in the darkness. Robin calls them ghost birds. They are most likely boobies, or maybe the large tropical tern with a split tail I saw yesterday. In the darkness, they catch the beam of green light from our masthead and the flash of their wings can look like a star, or a wave crest in the distance. But tonight they fly alongside us, the flapping of white wings in the green light. They seem a little unreal, like an old animated kinescope image of a white bird against a black sky, flickering in an endless loop alongside us on the dark ocean.