If you’ve had the unique privilege of witnessing bioluminescent plankton while diving at night, you know firsthand how beautiful the underwater light show can be. For those of us who haven’t experienced it, this unique phenomenon. So what makes this beautiful show possible? In a recent post at online scuba site AquaViews they share some insight we thought you all would find interesting.

Invented in 1920′s this could be world’s first navigation system. No satellites or digital screens were used in the making of this portable navigation system. Called Plus Fours Routefinder, this little invention was designed to be worn on your wrist, and the “maps” were printed on little wooden rollers which you would turn manually as you drove along.

An Extinction Rebellion protestor holds up a sign saying “You Can Change Climate Change” in St Martin's Lane in London, United Kingdom on August 23, 2021. (Photo by James Veysey/Rex Features/Shutterstock)

A gallery worker poses in front of part of artist Sin Wai Kin's Turner Prize shortlisted artwork “It’s Always You” at the Tate Liverpool in Liverpool, Britain on October 18, 2022. (Photo by Phil Noble/Reuters)

“You” star, American actress Victoria Pedretti locks lips with American actor Fred Hechinger in New York City on February 26, 2024. (Photo by The Image Direct)

A half-naked shrine parishioner using a wooden tub pours cold water onto himself during an annual cold-endurance festival at the Kanda Myojin Shinto shrine in Tokyo, Saturday, January 10, 2015. Pouring cold water on their bodies is believed to purify their souls. (Photo by Eugene Hoshiko/AP Photo)

Locals push a freezer after looting it from a shop, believed to be owned by a foreigner, during service delivery protests in Mohlakeng, west of Johannesburg, February 4, 2015. Local media reported that violence broke out on Wednesday morning when locals barricaded roads and burnt tyres during a service delivery protest. (Photo by Siphiwe Sibeko/Reuters)

A devotee takes a holy bath at the Balaju Baise Dhara (22 water spouts) during the Baishak Asnan festival in Kathmandu April 4, 2015. Devotees believe that the water from these stone spouts, which is collected from the catchment area of the Nagarjun forest behind the spouts, will cure pains and skin diseases. (Photo by Navesh Chitrakar/Reuters)