SACO — Thirteen-year-old Quentin Parker could barely believe his eyes as he walked onto the sand at Ferry Beach State Park.

Before him were five surf-casting rods, a tray of lures, a cooler full of bait, and charts listing the saltwater game fish of Maine – all courtesy of state park Ranger Glenn “Doc” Dochtermann.

Quentin and his family had come to the state park from Worcester, Massachusetts. While the rest of his family opted to swim, Quentin decided to race off to get his own fishing rod.

Within minutes he returned to join an informal group that had gathered around Dochtermann. The veteran park ranger was giving the latest in a series of free surf-casting lessons offered this summer at state park beaches. Participants only are required to pay the park gate fee, which ranges from $1 to $4.50 depending on the park.

The manager of Fort McClary State Historic Site in Kittery and Vaughan Woods State Park in South Berwick, Dochtermann is hopeful there will be enough interest in the lessons that the Bureau of Parks and Lands will allow him to continue next year. His next saltwater fishing lesson is Monday at Reid State Park in Georgetown.

At a class at Popham Beach State Park in Phippsburg, one woman came with her surf rod and asked Dochtermann to adjust the drag, which sets the amount of resistance a fish feels when it pulls on the line.

Even after a thundestorm ended the class, the woman went off on the rocks to fish by herself.

“About 30 people showed up for the class. But there were 1,000 people on the beach,” said Dochtermann, 67. “I’ve been fishing off Maine beaches since I was a kid. I’m surprised I don’t see more people doing it.”

Last week at Ferry Beach State Park, the group of about a half-dozen parents and children listened intently to Dochtermann. He quickly explained the type of equipment needed to surf cast in Maine, the types of bait that increase the chances of hooking a mackerel or striper, and where to go along a beach to find fish.

Dochtermann promised that surf casting done right can reward a fisherman with a mackerel, squid, pollock or striped bass on the line.

“My three children have been asking me about it, but they’ve never gone,” said Meghan Baldridge of Holden, who came to Ferry Beach with her three children, ages 10, 6 and 3, and joined the class.

“I’m not really knowledgeable. Personally, I’m squeamish when it comes to bait. So when they saw this they wanted to come over,” Baldridge said. “I hope it sparks some interest. They’ve fished in ponds and lakes, but I guess if they want to surf cast we’ll go buy some equipment.”

Quentin Parker, the young Massachusetts fisherman, was intrigued.

What are the mackerel feeding on now? Is his 10-foot saltwater rod suitable? How long should he wash his rod to get the saltwater off, and keep it from corroding?

He wanted to know it all.

After Dochtermann helped Parker place a piece of mackerel on his line and cast it out 20 to 25 feet, the boy stood quietly by himself for the better part of an hour.

Ferry Beach State Park Ranger John Hoyt, 34, also helped Parker. Hoyt explained surf-casting success is not just about picking the right size rod or the right bait; the location and time of day are important. Early or later in the day are optimal times, although there are exceptions, Hoyt said.

“It can be frustrating if you’re doing it wrong, but 10 percent of the fishermen catch 90 percent of the fish. If you keep the bait where the fish are and are patient, you’ll catch fish,” Hoyt promised.

Then there is technique.

Dochtermann told his audience how at a lesson at Fort McClary, he cast a lure in front of nine new fishermen and tugged on it to show them how to make it look like an injured minnow. Immediately, a gull came down and grabbed the lure.

“If you can fool a seagull, you can fool a fish,” Dochtermann said with a wink.