IANTD offers training on extended range and recreational trimix diving. You'll have to meet all of the prerequisit certifications such as advanced open water,and advanced nitrox. Technicle diving requires a lot of extensive training and work. You must be very disiplened with the preceedures and processes. Small mistakes here deliver serious consiquinces of the unheathy catigory. I have one rule I rely on thru all the years of my diving activities. Never dive past your education and training. Luck very seldom goes diving with you and when it does it's never a reliable dive buddy.