As a kid growing up on the docks in Campbell River, most fisherman just used to make their own herring rakes. A thin piece of board, like a trim board, with finishing nails pounded in one side and the heads of the nails cut off. You could sharpen the nails and use a one piece board not that glued...stuff.
The trick is to keep pulling the rake through the water and lift it up with the herring skewed on the nails. Pretty simple to make, give it a whirl..good luck