Velebit caves
The "Lukina jama" cave is 1431 m deep (2013), the deepest cave in Croatia, 14th deepest cave in the world and the deepest cave in southeast Europe. At its foot, there are ponds and streams including one of the largest known colonies of subterranean leeches ("Erpobdella mestrovi"), which has been ascertained to represent a new species, genus and also family. Other species discovered in the system, include the air-breathing land snails "Zospeum tholussum". Like Lukina jama, Slovacka jama, Velebita and Meduza are also located at the "Hajdučki i Rožanski kukovi" special reserve, a dedicated part of the Sjeverni Velebit national park.
Jarrod Jablonski
Jablonski has been setting records for cave penetration for many years. In 1995 he and Geologist Todd Kincaid pushed the Manatee Springs cave system to . On April 25, 1997, Jablonski along with George Irvine and Brent Scarabin set a new penetration record of in Wakulla Springs. They utilized Halcyon semi-closed circuit rebreathers at an average depth of . In July 1998 Jablonski, again diving with Irvine and Scarabin traveled in Wakulla Springs O-Tunnel. Jablonski and his regular dive buddy WKPP director Casey McKinlay set a world record for the longest ever penetration on a cave dive, at while exploring "Q" tunnel of Wakulla Springs.
This record remains the longest penetration in a deep cave. The new record for the longest penetration at any depth is now held by Jon Bernot and Charlie Roberson of Gainesville, Florida, with a distance of .