Marchena Island is one of the Galapagos Islands in Ecuador. It has an area of 130 square kilometers and reaches an elevation of 343 meters above sea level. The island does not receive visitors, although the surrounding water is used by aquatic divers on organized tours. People generally see the island as they sail around the northern part of Isabe…Marchena Island is one of the Galapagos Islands in Ecuador. It has an area of 130 square kilometers and reaches an elevation of 343 meters above sea level. The island does not receive visitors, although the surrounding water is used by aquatic divers on organized tours. People generally see the island as they sail around the northern part of Isabela on the way to Genovesa Island.