The 27-year-old is preparing to cast into the turquoise ocean that extends as far as the eye can see -- the same waters that North Korea is developing a plan to send four missiles into, less than 25 miles from where he stands.

"If it does happen, OK, it happens, but I just try not to really think about it," Martinez told CNN.

Martinez was born and raised on this small island of 160,000 or so people. They're used to living with intimidation from North Korea, including in 2013 when Pyongyang warned that the island was within its "striking range."

However, the latest round of tensions firmly puts Guam at the center of a very specific and potent threat.

A plan to fire four ballistic missiles into the stunning blue waters off the coast is being prepared for Supreme Leader Kim Jong Un by mid-August, state media reported Thursday. No one knows if or when the North Korea leader will give the order to launch.

North Korea's estimated splashdown of the missiles would place them just outside Guam's 12 nautical mile territorial waters, but well within its 200 nautical mile Exclusive Economic Zone -- waters where locals fish for tuna and blue marlin.

Guam's Homeland Security Advisor George Charfauros said Friday it would take 14 minutes for a missile fired from North Korea to reach Guam.

Guam has been a US territory for more than 100 years.

Like Martinez, most of the dozen or so residents CNN spoke to weren't panicked.

The US military has a large presence here -- its bases cover almost a third of the island's land area -- and prepares for worst-case scenarios like this.

However, that doesn't mean people aren't worried, said Jodiann Santos, who works at the Guam Museum.

"We're told to keep calm and that we're well-protected, but the reality is we could be here today and gone tomorrow," she said.

Jodiann Santos works at the Guam museum

The island's Governor, Eddie Calvo, has offered assurances, saying the island is well-protected, including with the THAAD missile defense system, which is specifically designed to shoot down ballistic missiles.

"There is no panic in Guam," Calvo told CNN. "I'm not trying to overlook it or understate it. We understand the threats, but we also don't want to panic anybody, and we don't want to jump to conclusions based on rhetoric."

As he fishes, Martinez says North Korea remains at the back of his mind, despite his best efforts not to think about it. And he's pretty sure he's not alone.

"Sometimes I feel like they fear it but they just don't want to show it, don't want to express it," Martinez said. "That's just sometimes how people are -- they don't want to show their fear inside."

Staff at Infusion Coffee are trying to perfect mushroom cloud designs on latte foam.

Mushroom cloud lattes

If there is fear among Guam's younger community, however, you wouldn't know it at Infusion Coffee.

The irreverent young staff behind the counter joke about the North Korean threat -- they're even trying to perfect a mushroom cloud design in the foam on their lattes.

"We take it lightheartedly," said Mark Alex, 26. "We also know it's very serious. We know that any moment, they could send those (weapons) ... but I think a lot of us in the end are not too worried."

Mark Alex, 26, works at Infusion Coffee, where staff are trying to perfect mushroom cloud designs on latte foam.

However, as customers sip on their coffee and grab lunch, Kim Jong Un's threat is what many are talking about.

But it's not the same talk of impending crisis you hear from politicians on the US mainland, a place where Guam is rarely seen on the news. People are worried about their families stressing out, not a nuclear showdown.

"Most people that live here, they've heard this before," said Aaron Burger, who's lived here more than a decade. "I'm really not concerned about it. We've been talking about this for more than two years."

The silver lining, in Burger's view, is that people in the mainland US now know more about his adopted home -- an island that was a Spanish colony before the US took control in 1898.

Burger said the news is prompting his family to ask him when he's coming home.

Local historian Malia Ramirez -- who specializes in oral history, the verbal passing down of traditions from the elders -- said he could sense the worry at the local laundromat Thursday.

Mothers told him they were "really apprehensive" because "you just don't know what's really going to happen."

"I know my sisters, because they have children, are concerned. I see it in their eyes. But they don't come out explicitly," he said.

No stranger to conflict

There's no sign that people are considering leaving, especially those who were born and raised here, many of whom belong to the native Chamorro population.

Guam is also a popular destination for Asian tourists, especially from Japan and South Korea but, for now, there are no real signs that travelers are canceling trips -- it's hard to to find a room at the resorts dotted around the island.

Guam, with its white-sand beaches, is a popular tourist destination.

The island is no stranger to conflict. It was occupied by the Japanese for three years during World War II and the July 21 Liberation Day holiday is one of Guam's biggest celebrations.

"If our past generations dealt with it, so can we," said Santos, the Guam Museum employee, who was born and raised on the island.

"There's nothing in the world other than God that would make me relocate and move away from my home."