Davide Marchetti

Marchetti runs Ghost Divers in Playa del Carmen, holds the world record for the longest solo cave swim — 8,592 metres over more than ten hours, set in May 2023 — and students name him in dozens of the shop's reviews. Unusually, a large share of his students say they found him on YouTube or Instagram before they ever contacted him. Several describe watching his videos while trying to sort out a sidemount configuration, appreciating what one calls his "no-nonsense approach and his sense of humour", and booking a one-to-one block on that basis; another researched cave certification for months and says his videos are what decided it. Many arrive already knowing how he teaches. What they describe once there is consistent. Training comes in long personal blocks — three days, eleven days, fourteen days — almost always one-to-one or in a pair, in a different cenote most days, with hotel pickup and drop-off included. The teaching is explanatory rather than declarative: "he explained things and the reason behind them", and when a student did not understand, "he took the time to figure out how to explain the same concept differently" — one describes days of failing to get body position right for navigation until a different framing landed it. Rigour and warmth come up together rather than in tension: "the training is fun but don't think it's easy or there is a short cut, there are NO SHORT CUTS". Reviewers mention him lending personal equipment, including his own computer, to get a rig right, and refusing to move on until a concept was genuinely understood. Repeat students are common, and several are diving professionals themselves. His guide Mauro is named warmly in the same reviews.