Sustainable Fishing, Marine Biology & Conservation

Background Pages

Blocker Rig Study

Single, non-offset circle hooks (I suggest the Mustad 39960D) are the ONLY way to go for shark fishing from beach or boat. However, as effective as they are in hooking sharks in the jaw rather than in the gut, it’s been my observation that circle hooks still have a 5-10% incidence of gut-hooking.

Observing this, we began experimented with different rigs and hooks that would help ensure that sharks would be hooked in the jaw every time. What we came up with is what we call a “blocker-rig” which is nothing more than a length of plastic pipe mounted perpendicular to the leader a specific distance from the hook. The pipe prevents or “blocks” the fish from swallowing the bait. We’ve documented  an almost 100% success rate of preventing gut hooking since we started using these rigs in 2008. The blocker rig works!

In 2010 we tried to determine if the blocker-rig is as effective at getting bites as a standard non-blocker rig. We fished both type of rigs side-by-side and record the results of every bite. Our records indicated almost a perfect 50-50 split showing that the sharks do not shy away from the awkward looking rig.

Blocker rigs are easy to make using PVC or any other type of plastic pipe. For small 3-6 foot sharks we use an 9-inch length of plastic tubing drill a hole through it’s mid-section and run our wire leader through the hole. Then, using crimps or twisted wire, the pipe is fastened to the leader 4-inches above the eye of the hook in a fashion that allows it to rotate but not slide up or down on the leader. When we expect larger sharks such as makos, blues, tigers, or sand tigers we’ll use 12 to 14-inch lengths of half-inch PVC mounted 7-inches above the eye of the hook.  For really large sharks such as big tigers we increased the length of the pipe to 24-inches and used ¾-inch PVC since they have such a wide mouth. On all rigs the measurement from the eye of the hook to the pipe (blocker) is important because if it’s too long the hook can still reach the shark’s throat.

Great White on the Blocker Rig

Underwater shot of an estimated 400 pound great white hooked aboard the Fish Finder and lost after 20-minutes on June 9, 2011 about 26 miles off Ocean City Maryland. Look close and you can see one of our PVC "Blocker-Rigs" off its lower jaw. The hook was in the front of the lower jaw and when the shark became un-tail-wrapped it got away. Of course it would have been released anyway.