Pacific colonization and geology. A day of light airs, shifting breeze, and the now quite usual battles with countless passing squalls. 

Polynesians colonised the Pacific Islands from a starting origin far west across vast distances. They sailed across the Pacific Ocean, the largest on Earth, over waters of great depth but also over shallow reefs, chains of submerged seamounts, the large mid Pacific Ridge. On their way encountering and making their home of the myriad of islands that pepper this Ocean.  

Cook, in turn, was impressed enough with both the practical seamanship and navigational skills of the Tahitians, and their wide geographical knowledge, to accept that which had been unthinkable to earlier European voyagers: that the ancestors of these islanders must have sailed into the Pacific on their own, covering great distances in their canoes, orienting themselves by observing the celestial bodies. Unfortunately, Cook never developed his thoughts beyond a few lines in his journal, which include elements basic to a modern theory of Polynesian settlement: an acceptance that Tahitian canoes were seaworthy and capable of sailing at least "two or three hundred leagues" (600 to 900 nautical miles), that the Tahitians had a "compass" provided by the sun, moon and stars and that they used this to orient themselves at sea, and that their ancestors could have employed this technology to move, from island to island, all the way from the "East Indias" (roughly modern Indonesia) to Tahiti. 

William Henry Giles Kingston. “Captain Cook. His Life, Voyages and Discoveries”. 1871  

Later on, we found out that they not just reached Tahiti but all the way to Easter Island. 

Aboard their canoes, they sailed from the islands that grow out of the convergence between the Australian and Philippine tectonic plates and the large Pacific plate, and all across this latter one until they reached the islands born out of a stationary hotspot breaking through the Nazca Plate, that subdues all along the South American Pacific coast. Convergent, divergent, or transforming boundaries. Earth’s mantle materials fracturing or puncturing through oceanic crust. Areas of high volcanic activity in the World’s oceans, where ocean crust spreads or sinks under continental rocks, the motors of the plate tectonics, the shaping of continents and oceans, the rise of the largest mountain ranges, islands, and ridges of submerged seamounts.  

From yesterday, within close range of our position, the Salas y Gómez Ridge runs from the vicinity of the coastline to Easter Island. The Sea Chart of the area where we sail now shows that in some parts rises about 3500 meters from the sea bed around. Nowadays just two of its volcanic buildings reach the surface, Salas y Gómez and Easter Islands. But not long ago, various others were as well, just during the Last Glacial Period. With large quantities of water forming large icecaps, the sea levels were up to 130 meters lower than today. The rest of the islands that emerged are now under the sea, but their tops carry the erosion marks from this period above sea level. They are known as Guyots. Many others never got the chance to break the surface and have always been submerged, those we call Seamounts. 

And today we passed some of them, though hundreds of meters below our hull. The next point where they emerge is our destination, Easter Island, today still 539nm ahead of us. After dealing the whole day with windless conditions, squalls, and light airs we just left behind 69nm during the last 24 hours, 

Above us and sweeping over the ship on several occasions, the common squalls, were already there from the early morning. Yet another day of our already quotidian brawl with their changing conditions was ahead. 

Beginning with a becalmed night, the journey was a constant struggle with light airs and just a puff of a breeze now and then, which Europa does her best to catch. 

During the morning, now we find ourselves encircled by passing showers, and then a bit of wind fills up squares and studding sails. The slow-moving squalls catch up with us. Finding ourselves directly inside them, it is time to look for a waterproof jacket as the pouring rain falls. But today it comes together with wild breeze shifts. Sails flap empty of wind; sails fall aback; we pull on the braces back and forth; the ship goes backward; she slowly turns around; she drifts on windless conditions; she eventually catches a puff of any kind of wind direction it would blow when still sitting in the middle of the shower. 

In the afternoon, similar conditions. Light breeze all over, showers pass by. Steering north, south, west, and everywhere in-between. Days like this, and situations like that really make for a difficult navigation. Nevertheless, long ago Polynesians sailed eastwards without the help of any modern navigation electronics, just with a great knowledge of the seas, its nature, movements, clouds, showers, and winds they did it all the way to Easter Island and beyond in their small canoes. 

After lunch, a bit of steadier bit of wind allows for trying the manta trawls that are planned every three days. So far so good, the first trawl out of three seems to work well. Then during the second sampling, the ship stops again. The trawl just hangs alongside us. We think to leave it for another day, while the crew pulls on braces again trying to take advantage of the large breeze direction changes. Square, close-hauled, beam reach, and then square again. The six Studding sails come down on deck and are packed. An hour later four of them are unpacked and hoisted again.   

The challenges of calm weather and light wind sailing.