It looks as if most (or all) of you are fishing salt water and my guess is that diving conditions in freshwater lakes is quite different.
First, I consider spearfishing as BOTH hunting and sport. As a hunter your goal is to outsmart your prey. Learn to think like they do so that you can learn their habits and know when and where they may be lurking. You have to learn whether they are going to be on covers or structures. You need to find covers of different depths and know what depth they may be in at different times of the year. You don't just drop down and spear a fish. You sneak in slowly from the side and once you see the cover (sometimes vis is only about 3-5 feet) you stop, hold your breath (since walleye are easily spooked) and wait to see if anything swims by. If not then you attempt to "call" them. As a sport, you are always trying to find the "big" one. I also try for a head shot, not just because I don't want to destroy a fillet but because I don't want my husband lecturing me on my shooting ability.
The only fish I seek are walleye and crappie. And our limit of walleye is only 2 and our season is only about 3 months long, so we tend to let marginal fish swim by so that we can pack the freezer with larger fish. Catfish are also legal in our area but I do not enjoy eating them, so we don't shoot them.
I don't understand the remark about banning tournaments since they are not "catch and release". We are still eating the fish that are shot. I don't shoot in tournaments but my husband travels to the gulf a couple times a year to do so. And using him as an example, I know when he is shooting competitively he comes home with fewer fish that when he just goes for the hunt because when you are shooting competitively you are passing up several legal fish in hopes of a "winner" swimming by. Thus, if you want to decrease the amount of fish that are speared, we need to go to tournament fishing only (I am not recommending this though).
Thanks for listening...