I pursued cave training for similar reasons. I had a passing interest in caves, but my first purpose was to prepare for overhead penetrations of wrecks and artificial reefs. I was shocked to find that cave penetration is much safer than wreck penetration. In fact, I now believe that I am not yet ready for wreck penetration, as in many ways each wreck dive is an exploration dive. Wrecks are subject to the conditions of their environment, which can effect significant changes on the internal structure of the wreck. Unlike most caves, wrecks begin a depth and stay deep, forcing the team to incur significant gas loading for even the shortest penetration. Furthermore, this decompression must be held in open water without visual reference, and deco gases must be carried throughout the dive, exposing the team to a possible CNS tox.