3rd Sea Day to Bora Bora - Day 29

Approaching the equator. If the oceans could be drained a vast topography would reveal itself: wide valleys, ravines, whose impossible depths plummet thousands of feet, enormous mountain slopes that rival the planet’s most majestic ranges from the Himalayas to the Andes. Fortunately, there is bathymeter, or sea floor mapping, which has provided astonishingly accurate images we can see. Check it out ladies, and Jatasya - so you can teach Indra. In 1912, the world’s first patent for sonar (Sound Navigation and Ranging) was filed in Britain in an attempt to make navigation safer. The device, first used in the 1930’s, emitted a beam of sound from ships into the water and measured the time it took for it to bounce back thereby creating a schematic contour of the ocean floor. The 1st full scientific map of the Atlantic floor was created by American geologist Marie Tharp (1920-2006). Today 100’s of parallel beams work concurrently to Hassan to process. However, mapping does not always occur from a boat. LIDAR or (Light Detecting and Ranging) is conducted from low flying aircraft. This method resembles sonar but used light beams invisible to the naked eye (of humans). Amazingly, satellites, too have been equipped to detect the minuscule differences in gravitational pull created by under sea mountains versus deep trenches. Understanding the seabed contours is not only important for nautical charts it also alerts scientists to beach erosion, tsunami forecasting, tectonic plate shifts, sea levels and of course government policies around the world. We had the Salute to Neptune - Pollywog to Shellback ceremony, a good time was had by all. Aoibhin, our cruise director had never crossed the equator.Read more