In the July 1999 issue of Hawaii Fishing News, Mike Sakamoto wrote an article about a jigging device used effectively by David Itano of the Hawaii Tuna Tagging Project at the FADS. The first figure shows the drawing in the article:

As described in the picture, David uses a 5-6' length of 20-40# monofilament attached to a swivel at one end of the wire. The main line is clipped or tied to the swivel on the other end of the wire. The lure on the 1/0 size Mustad 7766 or similar hook is either a strip of glitter minnow block or a plastic curly tail with silver glitter in clear background, firecracker (blue and red glitter in clear background) or transparent deep red. A gill net lead or molded lead of 3-5 oz. is fixed to the center of the rod.

I use a somewhat smaller version as shown below:

Note that my wire is bent somewhat. I feel that this allows the rig to settle properly with the leader and hook streaming out above it. I rarely get tangles with this approach.

A picture of the plastic curly tail on the hook is next:

This particular leader and lure hauled in a 40# yellowfin tuna, although it did take some time... ;)

I usually lower the jig to some amount below the school as seen on the depth recorder and retrieve it with large upward rod sweeps, retrieving line down to the water surface. If the fish are around, the rod simply stops after about the 2nd or 3rd sweep and the reel and I begin screaming. Party time...