So upon realization that the firecrackers in the state are illegal to begin with, and its a huge problem to attempt to scare away dolphin, I'm obviously just gonna have to deal with it. That being said, my smart ass response to your statement is...So even if you do go through the effort to shoot at, throw fireworks at, or bang on a metal pipe near dolphins, and you do succeed at driving them off, and you don't get busted and lose your boat and pay a 5 figure fine...what impact do you think all that noise is going to have on the fishing? I've seen slammed boat hatches stop a red hot bite in its tracks. Do you think you'll be able to drive away a group of 10 foot long predators and not bother a 15" snapper?
1. Are you fishing for reef fish in a 3 foot creek for boat hatches to scare them? Pretty sure the sound of diesel motors and outboards running, not to mention vibrations of the prop in the water and hull slap would be a little louder than a hatch slamming. Or how about the guys that drop a hundred pound anchor and chain of galvenized metal straight down on the fish, that doesn't seem to stop the bite...
2. That would be great if it stopped all the 15 inch snapper from biting so all you catch are sows in season.
Again, my search for a dolphin deterrent has come to an end, but i really don't understand your logic on that response about the hatches slamming.