SEA ISLE CITY — The freezers were empty this week at Mike’s Seafood, where glass case after case had a thick layer of chopped ice waiting for today’s deliveries.

The takeout seafood store will be stocking up on scallops, clams, flounder, tilapia and salmon for Saturday’s 19th annual Polar Bear Plunge, a three-day festival that generates summer-like business for a resort that normally goes into hibernation for the winter.

As many as 40,000 people are expected to come, if not for Saturday’s icy plunge into the ocean then for the bar-hopping and house parties that liven up this normally dreary February weekend.

Virtually the entire island is booked solid for the weekend, so Realtors are directing latecomers to try nearby Avalon or Stone Harbor.

The festival, which starts at 11 a.m. today with a Promenade ribbon cutting and is followed by the 6 p.m. naming of the Polar Bear prince and princess, helps sustain many year-round businesses during the slowest part of the year.

The seafood shop stays open weekends during the winter. But for last year’s plunge, they took 190 dinner orders — which would be high for a typical summer day, said employee Mike Scanlon, of Dennis Township.

“We have steamed clams, crabcakes, salmon and flounder,” he said. “Most people haven’t been to their summer home in months. They don’t want to stock their fridge because they’ll be leaving again.”

Mike’s Seafood founded and organizes the festival’s annual 5K race and 1.5-kilometer walk on Sunday, which raises money to help autistic children.

“It’s overwhelming for us because we’re so preoccupied with sponsoring the autism run,” Scanlon said. “We have to keep in mind we still have a business to run.”

All over town, merchants are getting ready for the crush of festival-goers.

Ellen Collins’ Red, White and Brew coffee shop opened in May last year. Collins said she solicited advice from other merchants about what to expect from her first Polar Bear Plunge.

Any extra business will be especially welcome this year. Like many other business owners in Sea Isle, Collins had to clean up after Hurricane Sandy. Her store was flooded with more than 3 feet of water that upended freezer cases and soaked the walls.

Her commercial landlord installed new wallboard, shelves and fresh paint in a matter of days so she could reopen.

“People said to expect this weekend to be even busier than a normal summer weekend. I hope it’s true,” she said. “I don’t know what to expect, but we’ll be ready.”

Down the street, Giovanni’s Delicatessen took delivery Wednesday of hundreds of pounds of groceries, meats, cheeses and cases of drinks. The deli’s specialties are its Italian hoagies and homemade meatballs.

The store’s shelves were bare when owner Lorraine Ciro, of Mays Landing, unlocked the door this week for the first time since November.

“We want everything to be fresh,” she said. “We’re expecting a very good weekend. We had to clean the whole store and restock.”

Ciro said she normally stays closed through March, but the growing popularity of the festival persuaded her to open early this year — the store’s 30th anniversary. Especially in the last three years, the festival has become a premiere social event in Cape May County.

“The snowier it is and the colder it is, the more they love it,” Ciro said. “It’s so huge. People have family reunions around it. It’s a big family event.”

The waiting lists for condo bookings on the island this weekend has grown so long, real-estate agencies stopped taking names, said John Burke, of Ocean City, a Realtor with Sea Isle Realty.

“There was just no point,” Burke said.

“We run into two things. Some people winterize their homes so we’re short available inventory. And it’s getting so popular, that people are booking early,” he said. “Phone calls started in earnest in December.”

He has been urging visitors to consider staying in Avalon, even if it means driving the long way around to Sea Isle City because the Townsends Inlet bridge is closed for repairs.

“There is no other winter weekend that we run into problems where we can’t find people a place,” he said. “It’s Mardi Gras. It looks like summer, but people dress a little warmer.”

Michael Cardinale, owner of the restaurant Mrs. Brizzle’s Buns, said the festival sustains his shop through the lean months.

“It’s like full-bore summer. Without this event, it would be really hard to survive the winter,” he said.

Stores like his rely on family members and call back summer employees to help for the weekend. Cardinale is flying his son home for the weekend from Coastal Carolina University.

“It’s one of the biggest weekends of the year for us,” he said. “Then we’ll go back to sleepy wintertime mode through St. Patrick’s Day.”

Contact Michael Miller:

609-272-7217