Summary[edit] Description: English: Blue button (Porpita porpita), Uthandi Beach, Chennai, Tamilnadu, India. About 1.5 cm diameter. Date: 4 January 2021, 07:56:52. Source: Own work. Author: Timothy A. Gonsalves. Camera location12° 52′ 01.596″ N, 80° 15′ 01.224″ EView all coordinates using: OpenStreetMap 12.867110; 80.250340.