“Technical" diving, how did that concept come about anyway? The diving has been around for a long time, but there was never any need to give it a name. About 20 years ago somebody coined the term to encompass a bunch of unrelated activities. At first it meant dives that broke rules established by agencies. Later, folks started including established, although not mainstream, specialties, like cave diving, in with the other unrelated types of diving under the "technical" umbrella. There are many different definitions, depending on your source. There is no agreed upon definition. "Technical" diving is a meaningless term. It means too many things to too many people. When you say "technical" diving I have no idea if you are referring to cave, mixed gas, solo, deep air, something else or a combination. If you are interested in mixed gas; refer to mixed gas; if it's cave; refer to cave, etc. Your message will be much clearer. Expertise in one type of "technical" diving does not carry over into another. "Technical" diving is a useless distinction that, in my opinion, we should all stop using.