I was using vacuumed bagged water that was repacked again, so double layer ice pack x 5off
Excellent stuff, till the snapper spines sorted them out, especially good in the much warmer shallows of the upper waitemata over summer

Now have 3 x hot water bottles that are iced down plus 3x bunnings thingy below
At best, only good enough..... find they don't chill the fish down fast enough even tho after a 4hrs trip, the hot water bottles are still 1/2 frozen
Have tried multiple ice packs from bunnings 300x250x18, not good enough, good for the first hrs or so

What are you using to chill down your catch, besides shop bought ice ?

I chuck 3 or 4 3l juice bottles with frozen water in the chilly bin the night before so the bins cold to start with then swap them out with frozen bottles out of the freezer the morning heading out.

I just use ice no worries lasts ages. 

The packs fit in my chilly bin perfectly and are quick to wash down, so pretty happy with them. They are large volume, so stay frozen for a long time, but the same could be achieved with frozen salt/ice in plastic bottles.

Rob Forts large ice pack & 4 x Coleman ice packs (6 x 5 x 2inch) plus 2x 600ml frozen water bottles not shown in the foto

enough room for 7 snaps 35-55 easily