 "Technical" or "Tech" (sometimes called "advanced") sidemount courses develop higher level sidemount skills with a focus on technical decompression diving with 3 or more cylinders.A higher level of equipment proficiency and diving skill is required; as additional deco cylinders will be added to the rig, enabling mixed-gas and accelerated decompression procedures to be conducted.These courses generally require the student to be already certified as a technical diver (when crossing over from a backmount tech qualification), or the student first learns tec sidemount as a prerequisite for completing further technical decompression training in sidemount configuration.