NEW PORT RICHEY — Eric Scharber and his 13-year-old son Wesley decided to spend Memorial Day fishing, but it wasn't long before all the other boats and swimmers out there on the gulf made them think twice.
Still, they were already on the water in their 25-foot bay boat so they stuck with it. They were rewarded with a sight they won't soon forget.
About noon, about 150 yards off Anclote Key, they were motoring through shallow water and spotted something strange.
Wesley grabbed his dad's phone as Eric steered toward it. Not too far away, a Pasco County Sheriff's Office boat was headed in the same direction.
Marine Unit Cpl. Mitch Bollenbacher got there first and saw a grey fin pop out of the water as people nearby yelled that it was a dolphin. Then a second fin appeared and Bollenbacher thought, "Oh, that's not a dolphin."
A hammerhead shark, about 10 feet long by Bollenbacher's estimations, started whipping around in the light green water to snap at lunch passing by.
"That thing's massive!" Wesley shouted from his dad's boat nearby. "He's a beast. Can we get closer?"
Bollenbacher grabbed his phone, too, joining the growing number of people recording and posting videos during the seasonal appearance of these oddest-looking members of the local shark population.
Hammerhead sharks, among two dozen shark species in the Tampa Bay area, are most commonly seen March to July and especially in May and early June. They follow the migration of their prey, including tarpon and stingrays.
Three species of hammerheads inhabit the Tampa Bay area, said Bob Hueter, director of the Center for Shark Research of Mote Marine Laboratory and Aquarium in Sarasota.
There's the bonnethead shark, most common of the three, just 4 feet long at most and known for its curved head; the scalloped hammerhead, up to 12 feet long; and the great hammerhead, most likely the species starring in all the videos because it swims close to shore to feed and generally reaches 12 feet to 15 feet though it can grow to 20 feet long.
Hueter said he's seen videos of great hammerheads accidentally beaching themselves while chasing fish before wiggling their way back in the water.
Despite their size, great hammerheads pose little threat to humans. Just try not to look like a tarpon, Hueter advises — avoid wearing shiny jewelry or brightly colored bathing suits in the gulf.
Scuba divers who spot them should hold their position and just watch, he said. It's a rare experience.
Swimmers should refrain from panicking but get out of the water if they can, he said — not because the hammerheads will come for them but because you never want to get between a hammerhead and its prey.
Usually slow swimmers, they speed up to strike.
Another piece of advice: Swim during the day because sharks' nocturnal vision will alert them to your location, and they'll go figure out what you are.
"You're going to be the only thing out there," Hueter said. "You're not on the beach with hundreds of other people. So you're at great risk to yourself to at least be investigated by a shark."
Bull sharks pose more of a threat in local waters because they're more common, have large mouths and an appetite for mammals and small fish.
Fishermen who catch a hammerhead should just cut the line. Despite their size, the sharks can die after only 15 minutes of fighting once hooked.
Their mouths and gills are small for their bodies so they can't breathe well if held out of the water or battling a fishing line. Lactic acid will build up inside them, killing them.
A new regulation from the Florida Fish and Wildlife Conservation Commission will require fishermen to cut the line as soon as they realize a hammerhead is on the other end. It takes effect July 1. Great hammerheads are not endangered but Florida state law prohibits harvesting them in state waters.
Contact Paige Fry at email@example.com. Follow @paigexfry.