If you're stranded on an island, a 'HELP' sign can actually save you — but there's an even better way to get rescued

• Three men stranded on a Pacific island were rescued after creating a "HELP" sign with palm leaves.
• A survival expert said lighting three fires is an effective way to send a distress signal.

Three mariners stranded on an island in the Pacific Ocean were rescued earlier this month after they made a large "HELP" signal by laying out palm leaves on the beach — a scene right out of a movie.

The men, all in their 40s, left Polowat Atoll, a tiny coral island that's part of the Federated States of Micronesia, on March 31, traveling in a small, 20-foot skiff. Nearly a week later on April 6, a relative reported them missing.

On April 9, US military forces rescued the group from Pikelot Atoll, another tiny island in Micronesia about 1,000 miles north of Papa New Guinea and around 100 nautical miles from where the men set out.

"In a remarkable testament to their will to be found, the mariners spelled out 'HELP' on the beach using palm leaves, a crucial factor in their discovery. This act of ingenuity was pivotal in guiding rescue efforts directly to their location" Lt. Chelsea Garcia, the search and rescue mission coordinator at the time the men were found, said in a statement from the Coast Guard.

A US Navy P-8 Poseidon aircraft discovered the mariners. They dropped survival packages, while the Coast Guard Cutter Oliver Henry was rerouted to Pikelot to rescue the men, whose boat had been damaged.

A survival expert told Business Insider the men were smart to create a signal, but that there may be even more effective ways of doing so to indicate to others you're in distress.

The universal rule of three

Cat Bigney, a survival consultant and instructor at the Boulder Outdoor Survival School, said that often the best way to get spotted by a rescue team is to start a fire, as a big smoke stack can be spotted from miles away.

And not just one fire, but ideally three. Three of anything is considered the universal signal of distress: three fires, three blows in a whistle, three gunshots. Think of the original SOS call, the morse code distress signal which consists of three dots, three dashes, and three dots.

Bigney said it's most effective to build the three fires in a row, as the succession of smoke fumes will signal to anyone who can see them that you need help.

"You want to use anything that's going to cause a lot of smoke" to build the fire, she said, such as green vegetation or damp wood —which produce more smoke because it burns at a lower temperature and results in incomplete combustion.

Depending on the circumstances, it may be best to wait to light the fires until a plane or boat is visible to ensure you are ready when a rescue team is nearby, and so they do not miss you.

Beyond fires, Bigney said it's ideal to create signals with contrast. So in the case of the men stranded on Pikelot Atoll, palm leaves against bright white sand may've created enough contrast to be seen easily from afar.

It's also generally recommended to spell out SOS, rather than a message like "HELP," in part because the letters in SOS can also be read upside down.

"Now what they did, worked," Bigney said of the rescued men. "So I think the take-home message is be creative and do something."

The Coast Guard said the men had access to food and water while stranded with their damaged boat. Bigney said it was not necessarily the most dire survival situation but that other factors, like incessant sand fleas or nearby predators, could make it hard for some people to think clearly.

"They did a good job. They thought to signal for help," she said, adding, "Oftentimes it is just a psychological game, in any situation."