Hi Matthewswanson1,
Well no, it does not sink, because you drifting with current or wind pushing you, so you would have a non weighted cuta trace with a duster, that you let out about 25 to 30 meter from your ski, and as you drift this bait(mackerel or sard or bonnie) will be drifting in the upper section of the water colum.
All depending on the speed you difting, you can put it out with a bait swimmer or a down rigged sinker, but it needs to stay off teh bottom, otherwise you get stuck and bottom fish will eat your bait.
As the waves rock the ski it also gives movement to the bait, and i presume it looks like a wounded bait fish to the game fish.
Cheers
Pieter