Boat encounter with the 2019 Java bioluminescent milky sea: Views from on-deck confirm satellite detection

Milky seas are massive swaths of uniformly and steadily glowing ocean seen at night. The phenomenon is thought to be caused by luminous bacteria, but details of milky sea composition, structure, cause, and implications in nature remain largely uncertain. Between late July and early September 2019, specialized low-light satellite sensors detected a possible bioluminescent milky sea south of Java, Indonesia, spanning >100,000 km(2). Upon learning of these findings, crew members of the yacht Ganesha reached out to confirm and share details of their personal encounter with this same event. Here, we document Ganesha's experience as recalled by the crew, compare their course to satellite data, and assess their photography of this milky sea.

Automated summary

Milky seas are large areas of uniformly glowing ocean seen at night, thought to be caused by luminous bacteria. However, their composition, structure, cause, and implications in nature are still uncertain. Satellite sensors detected a possible bioluminescent milky sea spanning over 100,000 km(2) south of Java, Indonesia between late July and early September 2019. The crew members of yacht Ganesha confirmed and shared their personal encounter with this phenomenon. Their experience was compared with satellite data, and the photography of this milky sea was assessed.