This design was made specifically to solve this problem! It has a rubber band and a pen-click-retracting mechanism on it, so that when the fish gives the initial tug, it releases the hook so that it pulls the fish into a pincer hold. The device has nails so that after being triggered, the fish will be attached to the hook, and your line!
note-the nails are not as malicious as they may seem, i have heard fish cannot feel the area around their mouths, and this area is very tough anyway. It is meant to hold them tight.
For this particular instructable i felt that it would be easier on me to hand write the procedure on paper and transfer it to the computer. Hand drawing the design saved me from having to get creative with the paint program. SO lets get right into it!
Tools and materials listed on a close up photo below
Step 1: First 4 Steps
step 1. disassembly of the back clickly part of a pen. By that i mean any pen with a button on the back that you can press to make it retract into the pen shaft or come out. I used a pen with a pencil sized diameter.
step 2. we use three components, a nail, hook, and the part that does the sliding inside the pen the male end. We need them to become 1 solid unit glued together very strongly.
step 3. Get out your cotter pin and diagnol pliers and cut it as shown in the picture.
step 4. Play with the clickly part of the pen. Note that the male end is not made to slide completely through the female end. We need it to be able to.
We are using the smallest drillbit you own and your drill or dremel; and sliding it along the path of the slider (the path that allows it to retract) . This shoudl allow it to move completely through. You may need to sand down the male end it if has a circle of plastic on it that also prevents is from sliding all the way through.
Step 2: Last Three Steps
note dont worry about the tape falling off in the water, step 7 should stop that.
step 6. Assembly. we slide the first part we made into the last part we made. The we attach a thick doubled up rubberband to the bent nail and the cotterpin. Make sure to bend the metal around the rubberband so that it wont fall off.
Attach your fishing line firmly to the same places as the big rubberband. This will prevent the fish from snapping the band and getting away.
step 7. Now use your thread to wrap up the exposed tape on the female end of the pen. I used blue. This holds down the tape and makes the hook look better.
Also, twist up the rubberband by twisting the hook in circles. This will create the torque needed to twist the male end when the fish pulls it out.