Two American sailors who were rescued this week after five months lost at sea had with them a year's worth of food, a water purifier and, according to experts, a lot of luck.

"There's a lot of details that we don't know, but the first thought that came to my mind was they got incredibly lucky," said Kyle McAvoy, a retired U.S. Coast Guard captain and a marine safety expert at Robson Forensic, a Pennsylvania-based technical expertise company. "Until more details are known, that is something that's very important to recognize."

The women were sailing from Hawaii to Tahiti aboard a 50-foot sailboat, a fairly common route that normally takes about a month to complete. But after a piece of the boat's mast broke and a storm flooded the engine, friends Jennifer Appel, 48, and Tasha Fuiava, along with their two dogs, drifted 5,000 miles off-course into the Pacific.

The women made daily distress calls to no avail: They were out of range of any stations or ships, the U.S. Navy said.

Little else is known about the voyage. The women said their boat was attacked twice by tiger sharks, and they said they survived off of a stash of oatmeal, rice and pasta, as well as water from a purifier that broke just before they were found by a Taiwanese fishing vessel around 900 miles southeast of Japan. The U.S. Navy ultimately rescued them.

Related: Two American Women Rescued After Five Months at Sea

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Dr. Derrick Fries, a boating expert whose instructional book, "Start Sailing Right," was adopted by the American Red Cross, said it didn't sound like the mariners had an Emergency Position Indicating Radio Beacon, or EPIRB, on board. The waterproof device can be purchased for under $400.

"They certainly had adequate water and food supply to survive that length of time. It's unclear whether they had water on board or a purification," he said. "But the first thing they most likely should have had is an EPIRB."

The device is about the size of a cellphone and is satellite and GPS-activated to send transmission signals wherever its user is, Fries said.

USS Ashland Command Master Chief Gary Wise welcomes aboard Jennifer Appel, an American mariner, on Oct. 25, 2017. Jonathan Clay / U.S. Navy via AP

"If you look at international races, those things are just standard operation equipment," he added. "If that was on board, at the point where they thought it was a real emergency, they could have activated that, and it probably would have been hours or a half-day before somebody could have reached them by helicopter."

It's also unclear whether the women filed any type of sail plan that would alert authorities that they were overdue.

McAvoy said having enough food and the ability to get fresh water was critical to their survival, but said backup communications could have helped them.

"Those were some very lucky ladies and dogs ... hopefully they realize just how lucky they are."

"The other question I would have is whether they had a satellite phone on board with battery backup once they lost the engine due to flooding and it affected their communications," he said. "Not knowing those details is where I think to myself, those were some very lucky ladies and dogs. I'm very happy they survived, but hopefully they realize just how lucky they are."

Their warm location helped too, the experts said.

"They're more in the central latitude area," Fries said. "Those are favorable sailing conditions. Certainly storms come up, but it's not an area that's known to be overly treacherous."

Sailors from the USS Ashland approach a sailboat on Oct. 25, 2017, with two Honolulu women and their dogs aboard as they are rescued after being lost at sea for several months. Jonathan Clay / U.S. Navy via AP

Rescues at sea after a prolonged period are rare, but not unheard of. In 2014, a castaway fisherman was discovered on a remote Pacific island after 13 months on a 24-foot boat. Jose Alvarenga survived off of raw fish, rainwater and his own urine.

The stories don't always have happy endings. In July 2015, two Florida teens went missing during a fishing trip, and their overturned boat was found two days later. The boys' bodies were never found.

The women said their rescue came just in time.

"I honestly believed that we were about to die within the next 24 hours," Appel told TODAY.