Call me paranoid or simply a blade enthusiast. I dive with 3 different cutting devices.
1. The first one is my Wenoka Big Squeeze dive knive. I attach that to my left leg on the inside (California style) to make it less prone to entanglement and more streamline. Also by doing so, i could simply access the knife with either my left or right hand. BTW, i got the yellow color one.
2. The second cutting device I have is the Spyderco Pacific Salt in yellow . Its a folding knife and I could just clip it on my BCD on the right shoulder harness. Its an easy access for either hand.
I love this knife. The H1 steel that they use is very resistance to rust. Maintenance wise, its like a titanium knife. But unlike titanium, this knife keeps it edge. I had it for a few years now and its still as sharp as the day I got it. Highly recommended.
Spyderco Pacific Salt Yellow FRN
3. The third cutting tool I have with me is the EEZYCUT Trilobite line cutter. I attach the sheath to the strap of my dive computer on my left hand for a quick and easy access. Awesome tool to have. I use this more than my other two cutting tool combine. Its a great product. I have a few different line cutter prior to this one, but this one, blows the other line cutter out of the water and into my personal dive museum.
EezyCut | emergency cutting tools
So thats my usual set-up. I dont really care much about the leg strap one. But when you are working on the boat as a dive master, its always a good idea to have a cutting tool with you at all time.