As to Leatherman's comments earlier, regarding the spear shaft. I have made one, although I cheated a little bit, drilling 1, 3/16" hole, just above the shaft's entry into the handle, with a drill. This could be done in the field, although a more "flared" version. with the #18 knife tip..."BUT"...it works very well once laced into position! Make sure to "start" with an 1 1/4" limb and "taper" it so it "drives" into the handle, making it...even more...secure.
I speared a large catfish on The Cahaba River and the teeth held it in place for an easy pull outta' the water!
Just Sayin',
Capt. Chris