Pavel Evgenjevič Demidov (also spelled Pavel Yevgenyevich Demidov; Павел Евгеньевич Демидов; 13 August 1971 – 23 August 2020) was a Russian speleologist, most known for his work in extreme cave exploration, especially as the leader of the Perovo-speleo team expeditions to Verëvkina cave on Arabika massif in Abkhazia, from 2017 the deepest cave in the world. Early life, education and career He was born in Moscow to Evgenij Pavlovič Demidov, a land improvement engineer, and to Elvira Ivanovna Mazeina, an electric assembly technician in missile production. After the School No. 668 (1978–1988) in Moscow he graduated in navigation at Odessa State Maritime Academy (1988–1994). The study included a year and a half at sea, sailing the Black Sea and the Mediterranean Sea on school's training and trading vessels. As there was no suitable job in the Russian merchant fleet for him at the time, he returned to Moscow in 1994. After different jobs, including a 7-month stint aboard a Russian fishing boat in Fiji in 2004 as a representative of ship owner, Tuna Fishing Company, he settled in industrial rope access. Speleology During school excursions to the mountains of Crimea, Western Caucasus and during yearly trips to the village Verhnjaja (Upper) Sysert in the southern Ural mountains, where his grandmother lived, Demidov developed an interest in nature and in mountain climbing. To get better acquainted with rope climbing he enlisted in the caving school of the Perovo caving club in Moscow in 2000. Peščera Zabludših (Cave of the Lost) of Alek mountain range above Sochi, close to the Black Sea was the first cave he visited, in February 2000. The cave, discovered in 1966, was often visited by caving schools as it is difficult enough and deep enough, to the terminal siphon at −420 m. Demidov and 3 other caving school participants: Pëtr Ljubimov – Petja, Konstantin Zverev – Kostja and Roman Zverev managed to bypass the siphon and discovered a new branch of the cave on the other side. They made 5 more expeditions in 2000, 3 to the same cave, one to a cave in the Skalisty Range, North Caucasus – and one to Verëvkina cave which was discovered in 1968, rediscovered in 1982 and in 1986 explored to −440 m. The expedition in 2000 was the first to this cave after the 1992/93 war in Abkhazia, and also the first expedition using the single-rope technique. As there