Pozzo del Merro
Site Overview
The Pozzo del Merro near Rome is the deepest flooded sinkhole in the world, plunging to about 392 m, an extreme technical dive reserved for the most experienced exploration teams. The shaft holds astonishingly clear water and a fragile, near-lightless ecosystem, descending through a vertical limestone throat. Diving is strictly for full cave certification with specialised gas and exploration training, and is governed by the strictest safety and conservation protocols. It is a once-in-a-lifetime challenge for the elite of cave diving. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers. The site rewards careful planning, good buoyancy and a respect for Italy’s marine-protection rules, and remains a favourite among Mediterranean divers.
Dive Briefing
"Brief thoroughly on the expedition plan, gas and the overhead protocol. Enter with a fully certified team, run continuous line, control buoyancy to avoid silt, and use redundant lights. Monitor depth and decompression meticulously, and exit the shaft on the team leader’s signal. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point. Follow your guide closely, monitor your thermal comfort and complete a safety stop before exiting at the designated point."
Signature Marine Life
Cave Shrimp
Troglocaris
Best: Year-round
Stalactite Fauna
Troglofauna
Best: Year-round
Spring Algae
Cyanobacteria
Best: Year-round
Bats
Chiroptera
Best: Year-round
Troglobiotic Worms
Troglochaeta
Best: Year-round
Safety & Hazards
- Extreme depth
- Overhead environment
- Silt out risk
- Hypothermia
- Decompression risk
- Disorientation
Traveler Notes
Who is this for?
Exclusively for elite exploration cave divers with full certification, decompression training and specialised equipment. It is an extreme, team-led dive demanding the highest level of skill and preparation. It suits confident Mediterranean divers who value dramatic scenery, wrecks and rich marine life over tropical abundance. It suits confident Mediterranean divers who value dramatic scenery, wrecks and rich marine life over tropical abundance. It suits confident Mediterranean divers who value dramatic scenery, wrecks and rich marine life over tropical abundance. It suits confident Mediterranean divers who value dramatic scenery, wrecks and rich marine life over tropical abundance.
Quick Stats
Dive Logistics
- Merro Exploration Team
- Lazio Cave Diving
Photography Info
Best for: wide_angle
Nearby Stay
Hotel Genzianella
Frasassi • 2km away
Hotel Foro Appio
Pastena • 5km away