We used to make our own Hawiian slings using SS tubing, PVC plastic,and surgical tubing. It is a lot of fun to spear fish. We used to do it everyday in the Bahamas but over there you are not allowed to use scuba gear so you have to snorkle or use a surface compressor. We used to also make hand spears which is just a 6' piece of 1/2" SS tubing with a loop of surgical tubing attached to the end. Our only problem was with sharks following you because of the blood in the water. We had to face down about a 12' - 14' tiger shark onenight coming in. When all you have is a hand spear it is not a fun situation especailly when you still have about 200 yards to go to shore.