Back now at 7:42 with "Gma" invaes Gates. The dangers of pleasure boating. So many people out on the water right now. So many boating accidents are totally preventable if you follow simple rules. Matt... See More
Back now at 7:42 with "Gma" invaes Gates. The dangers of pleasure boating. So many people out on the water right now. So many boating accidents are totally preventable if you follow simple rules. Matt Gutman has the details. Reporter: This year's july4thfire works are just finishing up when frantic calls come over the radio. We have a serious collision out here. The boat is breaking apart. Reporter: A deadly collision. Three boats, 20 passengers. A harrowing situation. People are in the water. I'm pulling one in right now. Three are injured. One not breathing. Reporter: Four people died. This is probably the worst accident I have seen in my 11-year history. Reporter: Last year, 4,062 boating accidents. 736 in Florida alone. Do we know what happened? We believe once the fire works display ended, traditionally, people try to rush to the nearest marina. Reporter: George and his team at the fish and wild life conservation commission are the primary law ens form agency on these waters. We wanted a closer look. We tagged along with him and his team for three days. What kind of things a you looking for when you scan the or rising here? He's listening to the radio. He's maintaining a proper lookout. Making sure he looks back occasionally. It's constant vigilance. Reporter: On a quiet day, still plenty of action. This boat is being pulled over by fish and wild life baud it's moored right in the channel. They say it shows a lack of common sense. And this jet skier may have broken rules. Did I do something wrong? Yeah. You had that open and you don't have a life jacket. Reporter: He's not wearing a life jacket and his lanyard, the cord to turn off the jet ski should he fall into the water. Today he's ticketed. What is the single dumbest thing you have seen? Kids not wearing a life vest is my pet peeve. Bow riding. People riding in the front of the boat with their feet hanging. Time and time again, a father rides over a daughter. Reporter: Sure enough, a few bow-riding right in front of us. Today, they're cite also. What is the number one key for boert safety here or anywhere? The bottom line is don't operate a vessel while intoxicated. Wear your life vest. Pay close attention to what you're doing on the water ways. Hold on. Reporter: Back on pra troll, a crisis unfolding. A boat full of passengers, sinking. And few of them know how to swim. A few more minutes, this boat would be underwater. With the help of this boater, they get everyone to safety. They started panicking. Reporter: If you hadn't been there, the boat would have gone down. For sure. We would have had O or two deaths because a lot of the people on board did not know how the swim. Reporter: Of the 560 people who died in boating accidents last year, 77% of them drowned. 84% of those were not wearing life jackets. Fortunately, today, none of those 11 boerts became part of that is itstatistic. Saved only people. Thank you, Matt. Life jackets are key.
This transcript has been automatically generated and may not be 100% accurate.