OK....
So as you drift along you approach a sandbank, lets say coming from 180' to 60' (as they often do in the CI's) this is indicated by the 'rip' - the small (or big, ask Martin about 2004... ) overfalls created by the volume of water being squeezed through the shallowing water column. This indicates the top of the bank - when we see this we know the boat is going over the top of the bank - by 'spooling' the reel, i.e taking your thumb off while in free spool the bait remains in the kill zone for longer, if you spool for long enough and have the righ lead on, the bait 'flies' up slightly in the water column, enticing Mr Tubbs along!
Hope this helps??
As for bait - killer last year was a fillet of macky, cut lengthways into two, most of the flesh scrapped away and a single nick with a sharp 6/0 fine wire through the little red ligament at the tail end - never comes off, remarkable actually.