Sharks are pretty common here along the Central Coast, but some locals say the sightings have gotten more frequent.Drone footage from Danny Martinez shows a great white shark near the Oceano dunes. He said its the biggest shark hes seen and estimates its around 18 feet.Rich Weisbecker has been surfing in Pismo Beach for over 30 years. He said its pretty common to hear about sharks in the waves.I've seen a couple of sharks breach all the way out …