When we first started using leashes, we used 1/4" rope and drilled a hole in the back of our skegs. Then we just had a slip knot to keep the rope onto our leg. Someone started using surgical tubing to soften the pull around our legs, and then it evolved into the hawaiian sling model, where a section of surgical tubing was filled with a longer length of rope and when the board pulled, it would stretch for a while then come flying back. A small improvement over the harsh jerk of the solid rope, but much more dangerous when the board flew back at you. Quite a few guys were speared by their boards, or impaled by a fin. Many boards were damaged when the line pulled and cut into the tail. Many legs and ankles were bruised from the harsh pull of the rope. The modern leash has evolved so much, with the swivel links connecting the leg strap and board to the line. The rail saver piece saves the boards from the damages we used to have all the time.
Just sew a flap onto the end of the velcro that wraps around and sticks so it won’t stick and gives you enough to grab. An inch or so would be enough. Wear the leash around the leg just below your knee. It’s easy to reach and pull off.
As much as I hate the long swim to get my board, I still don’t like what a leash can do. I hate it when the leash gets wrapped around my forward foot and then I can’t move my legs around. I have to do that silly dance to get the front foot free, and sometimes that’s enough to keep me from making the wave. I hate when the leash gets under the board and then gets caught in front of a fin. I find that I can surf for a couple of hours without ever having needed the leash. Then again, if I had a leash I would have gone for something I probably wouldn’t make, but held back because I didn’t have a leash.
A couple of thoughts… you shouldn’t be out in surf if a wipeout is going to be harsh enough to drown you. You should be able to handle the hold down, the twisting and turning, the over the falls again action that often occurs. If you can’t handle that, don’t go out. A leash will not save you if you can’t handle the turmoil of the wipeout. Now add to that the potential of your leash getting twisted around you maybe just your leg, maybe worse. You better be able to handle that as well. I’ve had times when I could tell the leash got wrapped around me in a bad way and that when the board pulled it was going to hurt. I had seconds to grab the leash and hang on to keep it from tightening up and messing me up. Sometimes you don’t have that time, or you can’t grab the leash before it pulls. That can kill you. I’ve been out on days that were right at the edge of my ability, and have taken clean up sets on the head, getting shoved down so far and then realizing there’s no board at the end of the leash. Then I have to swim in with a leash dangling from my leg. Had that one happen more than once, and ended up surfing the rest of the day with a leash wrapped around my waste like a belt.