PALMETTO BAY, Fla. -

For four years, Lance Corporal Jon Hammar Jr. fought in Iraq and Afghanistan, wielding a machine gun and proudly serving his country.

"All the guys loved him,” said his father, Jon Hammar, Sr. “He fought well.”

But it was a surfing trip and a family heirloom firearm that finally brought this Marine's mother to tears. About four months since he departed for what was supposed to be the wave chasing trip of a lifetime, the Hammars’s son is locked up in a Mexican jail.

"It's unimaginable," said Olivia Hammar, the former Marine’s mother. "You just try to take it one day at a time.”

The Hammars spoke with Local 10’s Ross Palombo at their home in Palmetto Bay. They said their son returned from war with post-traumatic stress disorder. The only that thing that could calm his nerves was surfing.

"It was sort of a needed respite for him," the mother said.

The former soldier decided to buy a recreational vehicle with another Marine and planned a road trip to Costa Rica. That plan came to a screeching halt at the border in Brownsville, where Hammar was stopped because he had his great grandfather’s shotgun.

"It's the smallest shotgun. No hard kick. Only shoots one shot,” said Jon Hammar Sr.

Even though he declared it, the ex-Marine was arrested and put in prison.

"It's just silly. Life in jeopardy,” said his father.

"It's just hard as an American to think this is the reality,” said Olivia Hammar.

Democratic Sen. Bill Nelson has sent a letter and other politicians have pledged to help. But four months later, Jon Jr. is still in jail and hope is running thin.

"He's frustrated. It’s like, ‘When is this going to end?’ You can only say it so long and have him believe it," his mother said.

Just before Christmas, the military family is fearing the worst for their loved one.

"And we're out of ideas,” said Jon Hammar Sr.

"I don't know. We're afraid. Just hope the government will get behind us," said Olivia Hammar.

Three generations of the family have served their country. The Hammars said they're hoping their country can serve them in their time of need. The ex-Marine's next hearing is scheduled for the end of January next year.