the float system will definitely work as long as the bait gets down to the depth of the fish.
but by all accounts the best method, as I find stated by a lot of anglers one that I'd agree to, seems to be a strip of mackerel belly fished very slowly (very slow retrieve) on a leadhead (to get it down).
the depth you fish at will depend where the pollack are located - whether they are sitting on the edge of a kelp forest mid-water (they tend to hang around within the kelp too and can be fished for over the kelp), whether they are located over a reef or on a wreck, or whether they are on the bottom; they can be found in all these places and more but these are the 'likely' places. The simple thing is to vary your depth to try to locate them.
if the pollack are there then they are usually easily caught. if they aren't there then keep moving the boat to other places to try to locate them.
I personally also find spinners and soft plastics every bit as good, it can save some hassle with needing bait and soft plastics with big single hooks can illimate catching a lot of the smaller 'nuisance' fish (if you find them a nuisance) and small coleys for example etc. Most things work, including feathers.
my 2 cents anyway. hope it helps
Last edited by chuckaroo on Sat Jul 08, 2017 12:27 am, edited 1 time in total.