The UK couple were back home within days …Most of us have never had to use a go bag. And most of us have never had to abandon a vessel in the middle of the night. But I venture that most of us would take comfort knowing that if we had set up a go bag and eventually had to use it, that we would not have to wait for consular assistance to get a travel document.
By all means have whatever you want in your Go bag, but your primary focus must be to be able to survive the sea and get back to land alive. Everything else is a secondary convenience.
I would suggest a neoprene jacket, a manually inflatable life jacket, essential medication, water in a camelbak bladder (it has a nipple to drink), candy bars/chocolate, swim googles, a snorkel as essentials in a Go bag at sea. If you have one a hand held VHF marine radio. Passport, local cash and credit card too, but they are not essentials to survive.