Who disagrees with DIR and why?

[FMT]

You make some interesting points. Let me counter with my opinion which may or may not work for your diving situation but may provide you with some points to ponder.

I give away my primary because it is on a long hose for ease of transit while exiting the dive in an OOG situation and is known to be working as I am breathing off it. I always know where my backup is because it is on a bungie around my neck. My backup should be working because I switch to it just to chcek it during several points in the dive. I am not worried about the time it takes me to switch to my backup as I can handle being without gas for 10 seconds or so while I get that reg to my mouth. My team member may not have that luxury so I am more concerned about getting him a gas source straight away. I adjust all my second stages for top performance and use adjustable second stages so I can detune them on the fly when necessary to prevent freeflow. I use both of my second stages at least sometime during the dive (in particular as part of my safety checks at the beginning of the dive) so I know they are working. As part of my team I want my buddy to be thinking of my welfare as I think of his. That to me is the way team diving is. If either of us has a problem we know that the other will help get us home to where "the grass is greener and the sky is bluer." DIR or not DIR I tow a flag unless I am diving from a boat in which case the boat has my flag. I do carry a surface marker buoy which I can use in many ways such as surfacing away from the boat or if I were to lose my towed flag or as an accessory buoyancy device. I think a number of DIR people carry a whistle when they think it appropriate but it is clipped inside a pocket not strapped to their harness so you wouldn't see it unless they needed it.
T