All hooks are not created equal, and choosing the right circle hook can be even more confusing than choosing the right J-hook. Most of us were raised on Js, so we don’t start with the same base of knowledge when it comes to circle hooks. To make matters worse, while J hook sizes and styles are fairly standardized, there’s little similarity between circle hooks from different manufacturers. You may be looking at a 6/0 from one company and an 8/0 from another, yet they are exactly the same size. So, how will you choose?
The first big decision you have to make, obviously, is size. With J hooks the rule of thumb is to match hook size to bait size, but with circles that goes right out the window. Instead, match hook size to the size of the fish’s mouth – and err on the side of going too big. Circle hooks with a small gap will have a very poor success rate when used with fish that have wide, thick jawbones. In fact, you’ll want a gap that’s at least twice as large as the width of the jaw. Otherwise the hook will likely slide right across the jaw and out of the fish’s mouth as soon as any tension is applied. At the same time, remember that it’s critical for the hook to be as exposed as possible – not covered up with bait – in order for it to do its job. Reach for a hook that’s too large, and you may have more hook than bait in the water.
Next, consider offset versus non-offset. The effectiveness of each can vary from fishery to fishery, but one consistent factor is that offset hooks are more forgiving on those who can’t stop themselves from jerking the rod every time there’s a bite. And, they also lead to far more gut-hookings than non-offset circles. In fact, to a large degree they defeat the purpose of using circle hooks in the first place. It can be difficult to even tell if a circle hook has an offset just by looking; to be sure, lay it flat on a hard surface with the eye off the edge. If a curvature causes any portion of the hook to raise up off the surface, the hook has an offset.
Finally, you need to consider the factors that you’d have in mind for any type of hook: thickness, barb style, a turned-back eye for snelling, shaft length, and so on. When it comes to these details, there isn’t much difference between circles and Js.
Should you use circle hooks in the first place? If you’re catch and release fishing, the answer is always going to be yes. Studies show they (non-offset, of course) lead to dramatically reduced gut-hooking rates. And overall success rates can be much higher in some fisheries, too.