July 29, 2006
Early this morning we started off next to the coast in calm, peaceful waters broken only by the pontoons of our catamaran. Standing on deck you can see shapes on the seafloor down to fifteen meters depth. This makes Ricardo’s quest for seagrass meadows a lot easier.
Today we are on a voyage of discovery. We are looking at two banks or small seamounts that show up on the map as dots, that we will be describing and mapping in greater detail. The boat cruises and turns back and forth over the site in order to develop a more detailed map with our new cartographic machine. From the point of view of any nearby vessel we must look very strange going in circles but with each turn we collect better information. The “OLEX” machine takes depth data using soundbeams and aggregates it into a geographic matrix. In the areas of the matrix that are missing data, it extrapolates by averaging nearby datapoints, adding new information as it becomes available. The result is a detailed map of the banks were we are going to dive.
Xavier and later Ricardo are seated by the screen, looking at the map and directing our captain Jordi on the turns needed to improve the image. While we are watching new high points and cracks appear as the resolution improves live on the screen. We can also turn the image or zoom in and out. It’s a great toy for map fiends. Ricardo uses it to infer where there might be important habitats and to choose the most interesting site to explore with divers.