I worried about my back. It went into spasm just a week before the scheduled start of a three-day trek through the Ten Thousand Islands on the Florida Everglades’ WildernessWaterway. Even sitting at my computer for long stretches aggravated the tightness in my muscles. How would they hold up to hours of tough paddling while seated in the cramped cockpit of a kayak, followed by nights separated from the hard ground by nothingmore than a thin sleeping pad?

I worried about the weather. The waterway, on Florida’s extreme southwestern edge, is just what its name implies: a watery tropical wilderness without shelter or even dry land for miles at a stretch. A wind storm or, heaven forbid, lightning would be no small problem.

I worried about the permitting process. The campsites on the 99-mile-long waterway, part of Everglades National Park, are widely spread and have limited occupancy, allotted on a first-come, first-served basis. But the earliest you can reserve is 24 hours in advance, in person at the park office, so it was impossible to plan the trip before it began. Given that adverse winds and tides could turn a four-hour paddle between campsites into a desperate 12-hour struggle to make dry land before dark, putting together an itinerary could be a high-stakes gamble.

I worried about provisioning. The sea kayaks we’d be renting were narrow torpedoes of boats, with tiny forward and aft storage compartments that would have to hold tents, sleeping gear, clothes, food and five gallons of water per person.

I worried about bugs. We’d chosen an early spring departure because in most South Florida winters, there’s enough cold weather to decimate the bug population. But this winter had been unusually warm. My old friend Gregg, a Miami native, had just been out in Big Cypress Swamp and reported the bugs as homicidal. When I asked him for an anti-bug strategy, he responded, “Suicide.”

A map locating Everglades City in Florida (By Laris Karklis/The Washington Post/The Washington Post)

My wife, who most emphatically was not coming on a trip where the nearest plumbing would be miles away, focused her anxiety on reports of escaped pythons, whose population had begun to explode in the ’Glades. I knew that, among all the potential dangers we might face, constriction by giant snakes ranked in the “not going to happen” category. Far more realistic was the possibility of getting lost. The waterway is short on man-made markers, and the endless chains of mangrove islands and bays create a labyrinth, with jigs and jags in the apparent coastline that make the difference between a pass and a dead-end impossible to distinguish even up close. I was planning on navigating with a two-decade-old sea chart and a compass, a task made more challenging still by having to study the chart from the cockpit of a moving, wind-and-wave-buffeted kayak.

In the days before departure, I lay awake strategizing, woke up realizing that I’d left something essential off the provisions list, spent the day obsessively hunting for tips in online discussions among waterway vets.

Seem like a lot of anxiety over a “vacation”?

No doubt, but I’ve learned that often the trips that require the most effort deliver the greatest rewards. This trip, a self-propelled journey into one of the world’s great remaining wildernesses, could become a nurturing memory for years to come. To be taking it with two old college friends I’d last traveled with in 1973 and with my 21-year-old son, Sam, who had miraculously consented to sacrifice part of his spring break to paddle with a gaggle of geezers, upped the ante to once-in-a-lifetime opportunity.

Gregg, a retired lawyer, and Peter, a college librarian in Gainesville, Fla., drove to Everglades City a day early to claim our camping spots. Sam and I met them at the Ivey House, a historic bed-and-breakfast that served as our expedition staging ground. On the drive into town, a tropical squall blew in. The rain came so hard, we couldn’t see 10 feet in front of us, and the wind gusted to 35 miles an hour. As we sat having coffee on the back porch, the rain passed, but the wind kept blowing from the west.

Even arriving early, Peter had been unable to secure our first-choice camping spot — a platform on stilts about eight feet above the water in one of the inland creeks, about a 10-mile paddle from the ranger station. This so-called chickee platform had been our first choice because it would have put the wind at our backs. The only other easterly camp sites were too far to make before dark, so we chose a beach site on an island encouragingly named Jewel Key, due west, dead into the wind, but only half the distance.

As we loaded the rental kayaks, it became clear that they’d carry only about half of what we’d planned to take. Our definition of “essential” quickly narrowed, and after an hour of increasingly ingenious compaction, we’d managed to stow just enough to feed, water and shelter us for three days. A windblown couple landing just as we were launching asked which direction we were heading, then shook their heads doubtfully at the answer.

Fortunately, the kayaks’ storage compartments were double-sealed, and we all wore “skirts” that fit tightly around the lip of the cockpit and clamped snugly around our waists, keeping the wind-driven waves from swamping us. Even so, the easily tipped craft tottered on the peaks of the biggest swells. If we paused to rest, even for an instant, the wind forced us back toward shore.

When three of us had finally made it across the open bay into the relative windbreak of some mangrove islands, we could see Peter, the least experienced paddler among us, still struggling far back. As he bulled his way forward, Gregg’s hand-held GPS device — which I found nearly impossible to read in the unlabeled profusion of islands — indicated that we had missed the pass that would lead us out to the island. But it was by no means clear where the entrance was.

Peter caught up, and we sheltered in a small cove in the lee of the mangroves. As we caught our breath, we stared mesmerized into the universe of arcing roots. They rose above the inflowing waves like so many twisting stilts, merging into thick grey trunks that slanted skyward, holding a crown of green above our heads. After the tempest, it was a haven we weren’t eager to abandon. Gregg volunteered to scout for the passage before we all struck back out blindly into the gale.

I thought he was going to paddle 100 yards around to the other side of the island and come back. But 10 minutes passed, and that didn’t happen. Then 30.

“If we go looking for him, he’ll have no hope of finding us,” Sam said. “We just have to wait here.”

Another 30 minutes went by. I paddled out and screamed Gregg’s name, blew the whistle on my life jacket. Both attempts were swallowed immediately by the wind. At one point, I heard something that could have been a human shout, but there was no telling which direction it came from. Then, nothing.

“He’s gone,” I said when I paddled back. “He couldn’t find us again, and he’s probably gone on to Jewel Key on his own. He’s got food, water, a chart and a GPS, and he’s the most experienced kayaker of us all. He’ll get there.”

But could we?

Luckily, I still had my chart and compass. But I’d been following Gregg, so I didn’t know where on the chart we were. We had no choice but to backtrack, paddle back into the bay and find the one marker we’d seen on the way out. I could then locate that marker on the chart and get a compass heading for the pass.

Backtracking took us thankfully downwind. But once we found the marker, trying to read the compass with the waves washing over the boat and the wind spinning me broadside was a challenge. When I finally managed, the compass seemed to indicate an opening that looked no more promising than the one we’d just come from. But it was our only shot, so back we went into the ripping wind.

As we pulled past the point of another island, distinguished from the other 9,999 islands solely by my navigational theory, the wind stopped. The clouds parted. The sun emerged, backed by God’s own depth of blue. And there in front of us was a clear channel through the mangroves. The water lay flat as a reflecting pond as we cut straight furrows through it, slipping along at a gratifying pace. A brown shadow in the green water ahead grew larger as it closed on the point of my bow, then broke in a graceful gull wing of a flipper about two feet from tip to tip.

“A manatee!” Peter and Sam cried simultaneously.

A quarter-mile later, the water stirred in a flash of silver. The floppy dorsal fin of a five-foot tarpon cut alongside the kayak, then submerged beneath it. The breeze now was nothing but a steady rustle in the tips of the mangroves, which, judging by their height, were ancient here, rising 50 feet above our heads. Fifty feet above that, dapper black-winged, white-bottomed swallow-tailed kites glided in lazy circles. A bald eagle hunted in the distance.

Soon we sighted a rare spot of dry land, which like so much dry land in these mangroves is the result of castoff oyster shells, the after-dinner detritus of thousands of years of settlement by Calusa Indians. We pulled over for a much-needed stretch and found, just inshore, the foundation of a 19th-century settler’s homestead camouflaged by the dappled sunlight streaming through the high branches. The ruins of the house’s one-time cistern and a seeping spring where the settler had once dug his well spoke of a self-sufficiency almost impossible to imagine in this isolated outpost. We ate hastily assembled sandwiches, then headed on.

At the end of the pass, two miles of open Gulf of Mexico reared ahead of us, rimmed by a chain of barrier islands. On the chart, if I was reading it correctly, Jewel Key was due west. Half on faith, we set out toward the now-sinking sun. Soon we could see a wedge of white in the crook of the apostrophe-shaped island. We paddled on, stroke by stroke, into the endless bounty of sea and sky, our minds progressively emptied of all thought by the repetition of our labor, the virtuous ache in our arms and backs, the almost imperceptible progress toward our goal.

About halfway across, Sam yelled, “I think I see a kayak on the beach.” I squinted, and what first looked like a piece of driftwood began to resolve. Then I saw a thin, gangly figure lope across the beach. I’d recognize that saunter anywhere.

Jewel Key is aptly named, tiny and perfect, rimmed by sugary white sand and palisaded by the sinewy roots of mature mangroves, bleached and sculpted by sun and surf. We pitched camp on a northern spit of beach between bay and gulf. A nearly full moon rose over the dimming coastline to our right as the sun sank into the now tranquil ocean to our left, kicking up a glowing paint box of color that spread across the sky and lit the moon orange.

As the light ebbed, we built the fire high with driftwood and waited for the bug attack. It never came. Either the day’s wind had swept them all away, or they’d never been there to begin with. And my back: healed. For the first time in weeks it was limber and pain free, a revelation. After I returned home, I began regularly doing an exercise that mimicked the twisting thrust of the kayaking motion, and I’ve had no further trouble.

That night, as the campfire consumed leg after leg of sun-bleached wood, we feasted on Peter’s simplified paella. Then as the fire died and the stars grew bright, we talked about our past and Sam’s future until the words ran out. All that remained was the bottomless depth of an instant in time we all knew we’d never forget.

Shroder, a former editor of The Washington Post Magazine, is the author of “Seeing the Light,” a biography of Everglades naturalist photographer Clyde Butcher.