Transcript for Warning for swimmers as sharks are sighted on both coasts

Before you head into the water this holiday weekend, a warning about sharks. A little disccerting to see that in the water. Great white sightings on both coasts have beachgoers on alert and erielle reshef is at rockaway beach with the images striking fear. Hi there, erielle. Reporter: Good morning, Dan and Paula. You may not see a great white shark if you head to a beach like this one this holiday weekend, but it's not out of the question as sharks come looking for food. This holiday weekend beachgoers advise to be on alert. With sharks swimming closer and closer to shore. Barry Curtis caught this close encounter while flying his drone off the coast of California. A shark coming dangerously near this paddleboarder and in another sighting this boat pulling two inflatable swans going through those same waters. The boat had no idea that those sharks were in the area. Because they were towing two giant inflatable pool toys with girls sitting on them and then there was a swimmer in the middle. Reporter: Curtis alerted a lifeguard seen here swimming towards the boat. Moments later everyone piling in for safety. In cape cod a rise in great white sightings, 150 expected this year. Nearly double the number from 2014. First responders are preparing for more attacks. Hoping to prevent pandemonium like at this beach in Alabama. But it's not you the sharks are after. They're shifting their habitat use to areas close to shore because that's where the seals are. Reporter: The bait, a booming seal population. Beckoning sharks to shallower water. We are not on their menu but be precautionary. Reporter: Officials warn never swim near seals and don't dive in at dusk or dawn. Those are prime feeding times for sharks. There are other simple ways you can protect yourself. Never swim alone and stay as close as you can to shore. Dan, Paula. Or stay out of the water. Paula's recipe is stay on the couch and watch TV. Or shark repellent. Bring a can of shark repellant. Erielle, thank you so much.

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