Your emergency fishing kit needs to be tailored a little to suit the sort of environment that you expect to find yourself in. As a lifelong freshwater angler, (I've done quite a bit of sea fishing too though) and being based here in Bucks about as far from the sea as I could be in the UK, I don't bother myself with things like mackeral feathers. I bought a spool of 4lb line from the tackle shop, a small tub of split shot, some hooks, sizes 14, 10, and 6, and few small Arlesey bombs (ledger weights).
I fitted all of the shot, weights, and hooks into the tub that the shot came in, then I broke out the strengthening flanges in the plastic line spool creating a space in there just right for the small shot tub to slide into. I unwound about 30 yards of the 4lb line and re-wound it all on one side of the spool and then wound about 30 yards of heavier 12lb line onto the other side. This way I can get to whichever strength line I want. With this set up I can expect to be able to catch fish from most freshwaters as long as I can find a worm or some insect to use as bait.
I will occasionally carry a few small jig lures in a seperate box as these will tempt perch, chub, trout and even pike if used carefully. I always fish the lures with a wire trace so that the toothy predators cannot bite through the line.
If I'm using the normal hooks and perhaps a worm as bait I can fish it freelined, ledgered, or suspended under a float. I simply make a float out of a reed or twig as and when I need to.
If I expected to be by the sea I would uprate this kit to include heavier line, bigger hooks and perhaps a set of feathers, although I have found that I catch far more fish from the shore with a set of the small luminous "Hokkai" rigs, Mustad "Shrimper" rigs or Sabiki rigs than old fashioned feathers.
This page shows the things I'm on about..
https://www.veals.co.uk/acatalog/Feathers.html