Heather Cook smelled smoke, and she knew they’d have to abandon ship.

The engine of their sailboat was dead about halfway into what was supposed to be a month-long trip. Cook, her husband Robert and their dog Bandit were left with no option other than being lifted into the Coast Guard helicopter already hovering overhead.

The Coast Guard rescued the couple and Bandit, a Maltipoo who turns 1 this week, over the weekend about 90 miles off Hernando Beach on Florida’s Gulf Coast.

They abandoned their boat, named “Here and Now,” on Saturday after a porthole that wasn’t supposed to open failed and began gushing water. Cook told The Washington Post on Tuesday that it “blew out” and “catastrophically failed.”

Petty Officer 1st Class Nicole Groll, a Coast Guard spokeswoman, told The Post the situation was dire. “They were basically dead in the water,” Groll said.

The Cooks were sailing to Biloxi, Miss., to attend a wedding. They left Port Canaveral on Florida’s Atlantic coast on Nov. 2 and planned to get to Biloxi on Dec. 1, making stops along the way.

They had left the safety of the marina in downtown St. Petersburg, Fla., nestled amid tony restaurants and a new $100 million pier, and sailed about 30 hours before realizing they had a problem.

Cook said she was at the helm Saturday when Robert was doing his routine check of the boat. Suddenly, her husband came up and told her: “We are taking on water. We are taking on water.”

Already, 1 1/2 to 2 feet of water had pooled below.

Cook said her 58-year-old husband spent most of the next two hours manually bailing out water as she bilged water back into the 6-foot seas.

“I swear I thought he was going to have a heart attack,” she said.

At one point, she said, she activated their digital alert that sent a formatted distress signal to authorities. The Coast Guard Sector St. Petersburg received the call about 11 a.m., according to a news release.

The water was unceasing. Then the boat’s electronic instruments began to go. Cook said the Coast Guard reached her on a handheld maritime radio. They told her they were already above the doomed sailboat. “God was on our side every step of the way,” she said.

Lt. j.g. Zovek Chapa-Errasti was co-piloting the helicopter. They tried to drop Petty Officer 3rd Class Kevin Peer onto the sailboat, but the sails were down and they couldn’t get him on deck. So, Peer plopped into the water near the vessel and the Cooks threw him a line so he could make it aboard. On the boat, Peer assessed the situation: bad.

Cook said Peer helped them bail, even thinking to plug the gaping hole in the vessel with pillows, and things were improving because the seas had calmed. But the helicopter was losing fuel, so they had to make a decision. It was hard to think about leaving the sailboat behind. “This is everything we have,” Cook remembers her husband telling her.

She looked at him and said: “No. We are everything we have. This is just stuff.”

The Cooks formed a plan to have a nearby vessel help them to shore, but that’s when she smelled the smoke. They were at least two days from shore with no way to mechanically propel or steer the boat.

So she asked her husband: “What’s it going to be, Captain?”

“We have to save ourselves,” she recounted him saying.

They grabbed their ditch bag with important documents, making sure to snag her wedding band and the eyeglasses they had taken off during the hard work of ridding water.

Cook said she got into the metal basket dangling from the helicopter before Peer handed her Bandit, who was wearing his own life vest.

Coast Guard footage shows the basket swaying as it reeled up Cook and Bandit. Beneath them the water rippled from the helicopter blades.

In the basket, she said Bandit was kicking and shaking from the wind and noise.

When she and Bandit were buckled into the helicopter, she looked down for the first time.

“Our boat looked very small,” she said. “I knew my husband was still on it.”

Robert and Peer were hoisted back into the helicopter. They were together and safe again.

“We just held hands and cried,” Cook said.

Soon after, she leaned over and told her husband of 33 years that she had forgotten the Harry Potter Lego Advent calendar set.

“The ridiculous things you think of,” she said with a laugh.

The pair met while both serving in the Air Force in Okinawa, Japan. They had each been deployed and faced life-threatening situations before and, thankfully, were able to keep their cool, Cook said.

“They were very grateful and happy to be back,” Chapa-Errasti said.

He said it was a good thing that they had all their equipment registered because it was easier to find the vessel and confirm that it was in trouble. And people rarely have a life vest for their dog, so he deemed them prepared. The couple had honed their skills over nine months of sailing, setting off from their home near Tampa for occasional trips. But after their ordeal over the weekend, Cook said they are done.

Both from Southern California, she said they love the ocean but will now get their traveling kicks from their RV or on a cruise.

Cook spoke to The Post from their RV just as it reached Montgomery, Ala., with Bandit in her lap. She was excited that she was going to hold her grandchildren before she went to sleep again.

Though she didn’t have the Advent calendar, Cook managed to get a few items from the on-base store after they landed: a Coast Guard sweatshirt for herself and a Coast Guard leash for Bandit.

“I have a new favorite branch of service,” she said.