Guys
I always have a spare air system attached to my life jacket, it gives you about 2 mins of air for about £200. Having experienced cold water sudden emersion and having seen test results you are unlikely to hold your breath for more than 20 seconds !!
I am always shocked at the number of people who cross water with no life jackets or emersion suits, I have even heard emersion suits are too expensive ! and this from someone flying a new squirrel - what price your life ? Shame to auto in and get out and the drown waiting to be picked up !