Far and above, the TDI Cave Diving Instructor rating is an outstanding accomplishment few can claim. Arriving at Cave Diving Instructor Evaluation, the candidate has conducted at least three Intro to Cave Diving courses as well as having assisted in at least one Cave Diver Course. Following the format as Cavern and Intro, the candidate, having been recommended a TDI Cave Instructor, will demonstrate many of the Intro skills as well as now adding academic subjects such as gas matching procedures for example. Additional in-water skills include air sharing through restrictions, lights out drills and traverses, gaps and circuits.