As far as summer adventures go, Florida brothers Ralph and Robert Brown are racking up plenty of lasting memories on a boat trip across the Atlantic.

Dodging icebergs. Coming face-to-snout with a shark of "Jaws" proportions. Cavorting with a school of whales. Learning man can live on cold beanie weenies and fruit cocktail alone.

Even more thrilling is that they've completed two-thirds of a 6,200-mile journey on a 21-foot flats fishing skiff that many skeptics doubted from the get-go.

"We're more scared of failure than we are of the elements," said Ralph Brown of Spring Hill, speaking by satellite phone today about 200 miles off the southern west coast of Greenland.

With gusty winds whipping around him, Brown described how someone accustomed to Florida's steamy summer weather is dealing with the chill of navigating the open seas far from the equator on a boat with no cabin.

"What's the temperature out here? Just call it cold," he said. "I'm wearing long underwear under my survivor wetsuit."

And with the water temperature in the 40s, "falling overboard is not an option."

The Browns left the dock at downtown Tampa's Marriott Waterside on June 27 for the seafaring adventure that aims to raise $3 million for military charities and break three world records.

For Ralph, 50, the trip also is making good on a promise he made 29 years ago, when he was serving in the Marines. Three of his comrades died in 1980 in a botched mission called Operation Eagle Claw, in which several branches of the military attempted to liberate the American Embassy in Iran after terrorists took the ambassador and his staff hostage.

Brown vowed then he would one day find a way to honor the men who sacrificed their lives in that mission.

By taking this voyage from Tampa to Hamburg, Germany on his flats boat, called Intruder-21, he's hoping to garner enough media attention to sell at least 150,000 polo or T-shirts with the slogan "Do More Than Just Say Thanks." All of the money raised after trip expenses will go to the charities identified on his Web site, www.crosstheatlantic.com. Among them: Special Operations Wounded Warrior Foundations, Disabled American Veterans, the Wounded Warrior Project and Britain's Help for Heroes.

He also hopes to break a few world records along the way. If the brothers complete the journey on the Intruder-21, it will be the first Atlantic crossing in a flats boat; the longest ocean journey in a flats boat; and the longest unescorted flats boat voyage.

Ralph and his brother, a 51-year-old painter from Merritt Island, are experienced seafarers. In 2007, the pair made a 1,700-mile trip on the same boat from Atlantic Beach, N.C. to Bermuda to New York Harbor - a feat that put them in the Guinness World Records.

This time the cause is more altruistic, with the Browns using the attention to help fallen and wounded military.

So far, "we're behind in donations and we're behind in schedule," Brown said. The trip that was planned to end in 48 days may take an additional two weeks. But as they get closer to their final destination, they expect more interest in what they're trying to accomplish.

"In the beginning, I think people considered us a little crazy," he admitted. "We're proving so far that this can be done."

They're at a crucial point in the journey, where the at-sea legs go as long as 1,000 miles. Weather reports promised "calm winds and smooth seas" in this stretch before Labrador, Canada and Greenland; those reports proved wrong.

"Fighting the winds, our gas mileage has gone from 3 miles a gallon to 1," he said. "With a 347-gallon tank, they're not at the panic point - yet.

There's not much down time for the two-man operation. The brothers trade off working and sleeping, which requires being tied down. They miss hot showers and real toilets, and will no longer have warm food, with the recent demise of their 12-volt Crockpot.

Suzuki, which provided engines at a discounted price, also donated a banner for the trip. It was promptly put into service as a sleeping blanket. When it caught a strong wind and flew away, the Browns went on a mission to retrieve it. Until it landed in the water near a shark "bigger than our boat." Good sense prevailed, and their beloved "Suzuki," as they called it, was abandoned at sea.

Brown said their minor inconveniences need to be put in perspective.

"We chose to do this," he said. "What our military people go through day in and day out is a true sacrifice. And this journey is all about honoring them."

Brown, a father of three teens and member of Northcliffe Baptist Church in Spring Hill, said he has no doubt that "God's presence is with us." Although he can't read his Bible on board as much as he'd like - spraying saltwater prevents that - he is counting every blessing they've had along the way.

Like last Sunday, when the brothers attended a service at United Church of St. Anthony on a stop at an island in Newfoundland. Of all the churches, of all the islands they could have gone to, they ended up at one with a special service that honored fallen military heroes.

It was no coincidence, Brown said.

"It just shows you that no matter what, God is in charge," he said. "This is in his hands."