cubandiver:
One of the factors that persuades those responsible for managing our game fish to take the easy way out and simply outlaw spearfishing is the abundance of individuals like yourself that don't respect the existing rules.
I will no longer be able to spear obviously abundant fish because it will require too much work on the part of the game wardens to figure out if I am going to spear a protected fish.
Do you have any idea what a casual swim through the reef 500 years ago would have looked like? How about 50 years ago? If you talked to one of the guys that was spearing in the early 60s I bet they could describe what abundant grouper look like, and I bet it wouldn't even be close to what you see now.
Maybe you think those 500lb fish have had there time, and are now just eatting too many fish themselves. If so you are missing their main contribution: their offspring. These large fish lay tens of thousands of eggs, which when they hatch, form an integral part of the food chain in the sea. Without all these tiny fish and larva, much of the plankton and algae floats on by, instead of being transformed into the flesh of small fish which in turn become the flesh of larger fish, and so on, and so on. The food chain is broken, and all life in the sea suffers.
If you think you know so much about what should and shouldn't be fished then, by all means spread the word. But don't udermine the only mechanisim we have for ensuring that those fish will always be there for our children and our grandchildren.