As I am mostly out with people who are not familiar with driving boats at all, my safety brief is to push the red button on the DSC radio for 5 seconds until it bleeps, then wait for assistance to arrive. I do not want anyone who has never driven a boat before trying to start the engine and attempting to come and get me
so I don't tell them that a spare killcord is onboard.
In a leisure not commercial environment if I was out with other competent people, then my safety brief is that everything you may need is in my grab bag (killcord, safety knife, basic first aid kit, handheld VHF, handheld GPS). Thinking about it I may put a throw line in my grab bag for this season.