Sailing in Green Waters

The experience of long-distance voyages made pilots develop new skills, including training their eyes to read the different colors of the waters. Why were colors so important?

Vicente Rodrigues’ first rutter (c. 1575), first published by Linschoten, informed that near the Bay of Arguin, the pilots could see “water of green color”. If the green water was seen “twice”, it was a clear sign of proximity to the continent, otherwise, the ships were closer to Cape Verde’s Islands. This information was crucial to the safe continuation of the journey.

We can find the description of green waters also in connection with the Brazilian Run. In fact, the chief cosmographer Manuel Pimentel (1650-1719), in his collection of sailing directions, wrote that in the Maranhão basin there were many dangerous sandbanks of different sizes. The biggest ones were typically introduced by green water. The same author describing the sea route from Tobago Island to Cartagena de Indias noted that the pilot might see “very green water at high sea”. In any case, the pilot should not be afraid, because this water should be interpreted as a good sign (“não tema nada [o piloto], esta agua é certa”).

According to this rutter, the color of water could be very different in a certain place, depending on the season of the year. In the proximity of the Andaman Archipelago, in September, the surface of the sea was like a patchwork, full of spots, while in May, when rainfall was insufficient, the water was fully blue.

The nuances of water helped pilots not only to identify the location of the ship, but also to understand atmospherical phenomena which were previously unknown. [Luana Giurgevich]