Inflated lifting bags are seen attached to a ghost fishing net as volunteer divers of the environmental group Ghost Diving work near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 23, 2020. Divers removed half a tonne of abandoned fishing gear covering a British submarine that sank off the Greek island of Kefalonia in 1941 as well as other wrecks in an effort to protect the area's loggerhead sea turtles, dolphins and monk seals. Giorgos Kolikis/Ghost Diving/Handout via REUTERS

A volunteer diver of the environmental group Ghost Diving swims near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 25, 2020. Lost fishing nets - known as "ghost nets" - wrapped around shipwrecks often turn into death traps for marine life. Cor Kuyvenhoven/Ghost Diving/Handout via REUTERS

A volunteer diver of the environmental group Ghost Diving swims near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 25, 2020. Last week, Greek and Dutch volunteers dived 52 meters into the waters between the islands of Kefalonia and Zakynthos to remove nets entangled around HMS Perseus, one of the biggest submarines of World War Two and a cultural heritage site. Cor Kuyvenhoven/Ghost Diving/Handout via REUTERS

A volunteer diver of the environmental group Ghost Diving swims next to ghost nets, near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 26, 2020. The cleanup mission focused on the submarine's conning tower and the front outer hull. Giorgos Kolikis/Ghost Diving/Handout via REUTERS

A volunteer diver of the environmental group Ghost Diving swims near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 24, 2020. The nets recovered will be regenerated together with other nylon waste and used for the production of socks, swimwear, and carpets, it added. Giorgos Kolikis/Ghost Diving/Handout via REUTERS

Volunteer divers of the environmental group Ghost Diving work near the WWII wreck of the HMS Perseus, off the island of Kefalonia, Greece, July 26, 2020. Cor Kuyvenhoven/Ghost Diving/Handout via REUTERS