Maritime archaeological explorations have been initiated in Goa waters for locating shipwrecks and port installations in coastal waters and riverbanks. Explorations have been carried out in Sunchi Reef, St George's Reef, Baga, Grande Island, Aguada waters and Gopakapattana. The explorations at Sunchi Reef have brought to light shipwreck remains of an early 17th century AD. The evidence suggests that the wreck belong to the Portuguese Period. The exploration off St George's Reef has revealed the remains of the 19th century shipwreck of the Basel Mission Company. Further, underwater explorations brought to light stone anchors from Sunchi Reef, Grande Island and Baga waters and a number of iron anchors have been retrieved from Aguada waters. Onshore exploration and trial scraping at Gopakapattana revealed stone walls of well- dressed laterite blocks running perpendicularly as well as parallel to the river Zuari. At some places the walls lie buried in the sediment and have also been discontinued. Several bastions occur at regular intervals along one wall; six stone steps lead from the shore to the main wall.