No. The leashes are for getting in and out of the water and in case the loop bungee breaks or comes off for some reason. They don't hold the cylinder up under water. Save for the leashes on my LP50's that I may use with a ring system on my DR LT tech. The ring system is made to clip the leashes to. But they use a choker to the valve so they don't dangle.Do you have any images please, I don't remember seeing a set up without some form of bungee loop, how do they stay tight, just by virtue of the distance between anchors?
Ring system