Transporting fish home for the table

Probably sounds a daft question,but what is the normal procedure for keeping fish from going off ?
My brother is talking about salting them in a coolbox,is this needed?
Probably only be a few mackerel.
They could get a bit warm on the trip back to Manchester.

50/50 mix of ice and water in a coolbox so its like a slushie. Keeps them cold without freezing them and stops them drying up

Thanks Si,I wouldn't have access to ice,but I suppose what's left in the ice packs after a day out,and a drop of water might do the deed.
I've got loads of ice packs,a cool bag and a coolbox,so I could do a juggle with the bait and the coolbox on the way home,and put the ones for the table in the coolbox.

2 or 3 bags of ice from a supermarket will do. Only £1 a bag

simon parry wrote:

2 or 3 bags of ice from a supermarket will do. Only £1 a bag

If I remember right,there's a supermarket just over the iron bridge,I'll nip in there for some.

Thanks again