Sport Divers tend to attach the cutting device (knife, eezycut, scissors etc) in various places (BCD, body – arms or legs), based on their personal preferences and activity performed.
As Technical Diver, you are performing a different kind of diving, including using of mixed gases & deco obligations or in an overhead environment. Or any combination. And as part of your extended planning, risk assessment should be on your dive preparation planning list. And cutting devices are part of your equipment, by default. Good quality tools!
When performing a dive inside of a wreck (overhead environment: caves, mines, wrecks), or around a wreck, your cutting device plays a very important role in your safety. Lost or handing cables, ropes, fishing lines or fishing nets, even carpets or pieces of furniture may represent a great danger underwater. And even greater when you are obliged to perform a deco stage or you have no clear “physical ceiling” (in an overhead) and you get entangled. And the time is counting down faster! While on the dry land you can easily rich your diving tool in almost any position, no matter where your knife of eezycut tool is placed, underwater is totally a different story.
You’ll be bulky, even in sidemount, sometimes in tight space and therefore, reaching your cutting tool must be easy and with minimum physical and mental stress.
You must be able to access your cutting tools (knife, eezycut, scissor) with both hands. No leg mounted or Rambo style.
Try and follow the KISS principles: Keep It Stupid Simple!
Stay safe & Have fun dives!