I use one of those self retracting clips. It is attached to the boot and I clip the retracting end to a D ring on the other side of my chest. That way teh computer/compus/SPG is in front of my chest where I can find it, and to use the compus all I do is pull it out away from my body and into position. When finished it zips back aginst my chest, out of the way.
I don't like the wrist mounted computers because every diver I have been in the water with looses their wrist mounted computer/compus/depth gauge when the wrist strap unexpectedly come undone. Yea, I know it's not DIR or PADI or what ever philosophy, but I have never lot my computer.
Simple lanyard on a clip works for me..I prefer to keep all instruments on a console..Less chance of lost in or out of the water or on the beach/boat.If anything on wrist it would get in way of work or grabbing bugs. Never had a diver loose gauge on a console,seen a few that had been lost from going on wrist.Also easier suiting up if on console,no time wasted trying to place on wrist in hot sun wearing exposure suit.