Check lists are cool and they save lives
I can’t really emphasise how much I agree with this statement. Safe rebreather diving is all about being dilligent, and making sure that you have set up and pre-dived the rebreather correctly. There is no better way to do this than via a check list.
From an expedition (or training) point of view, having a paper sheet that is filled in for each diver and kept is a great tool. I know that this isn’t the ideal option for your average recreational diver, but a laminated copy in the back of your wet notes does the job fine. Check it off mentally as you go through it.
I particaually liked their use of witnessed events, such as each diver must have another rebreather diver witness them inserting a freshly packed stack into the unit.
It’s also great to see divers pinching their nose during a pre-breath.