Navigating unknown waters can be simple with a chart plotter or, on a calm day, even a good old nautical chart. But how about using just a fuzzy memory and a dream? Not so easy. And that is why, after exploring a lonesome mountain lake in California’s High Sierra range last year, as my buddy JG and I piloted through a narrow channel and around a point to discover a flawless cove, elation reigned. Protected by a granite promontory windward, this quiet haven featured clear snow-fed shallows, a broad hard-packed sand beach framed by shimmering aspens, and beyond them, a web of Jeep trails shadowing towering peaks.

It was, in a word, perfect. And I was lucky to find it, because ­although I had been here once before, it was only in my imagination. Ten years earlier, I had stood on the far shore of this same lake while driving through the area. A two-lane road skirts one side of the lake, but there on the far side, amid the craggy hills, I made out the faint outline of those trails.

Fast-forward to 2018, and the discovery of a neglected 1970 Chrysler Sport Fury boat online — and the memory of a little 1969 Honda Motosport 90 (aka SL90) trail bike moldering in my own garage — made the answer clear: Turn a sport boat into a nautical pickup and go find those trails.

A Classic Boat and Two Classic Motorcycles
The 16-foot Chrysler trihull proved to be a capable platform.Seth DeDoes

"Ad" It Up
After all those years of dreaming, a random Craigslist search ­kick-started the adventure. I responded to the ad and found a ­16-foot Chrysler trihull in a dirt lot. Its formerly gleaming Pirate's Gold hull was chalky and dull, its interior moldy, and its 85 hp Magnaforce outboard entangled in creeping vines. I fell in love. I opened my wallet. I bought it.

Soon I became infatuated with the fact that the boat, motor and trailer were all produced by the mighty Chrysler Corporation during its immersion in boating. Most importantly, though, I liked its shape. Hardly beautiful by ­marine-design standards, ­Chrysler’s ­“cathedral hull” runabouts debuted in 1969 promising superb stability, affable ride and handling, great value and roomy interiors. And it was the generous floor area that hooked me, because the ­cockpit, measuring over 6 feet long and 5 feet wide, matched a pickup bed in size, which, as ­every hillbilly knows, is just right for ­carrying dirt bikes.

A Classic Boat and Two Classic Motorcycles
The 85 hp Magnaforce outboard needed some work, but eventually it came to life.Seth DeDoes

Getting Started
Unlatching the Chrysler's engine cover, I found a rat's nest of wiring, hoses, rods, bell cranks and belts. Alas, this mess wouldn't run when I hooked up a fuel tank and battery, and turned the key.

Unlike a classic bike, which uses gravity to fill the carburetor bowl(s) with fuel, the Chrysler outboard has a vacuum-operated pump to deliver premix from a 6-gallon tank to three Tillotson side-draft carbs. The starting process requires squeezing a rubber priming bulb to lift fuel from the low-lying tank to the fuel pump. And that wasn’t working, due to an air leak at the quick-disconnect coupler. Rats.

I sourced a new coupler from the local marine store and, after removing the float bowls and cleaning the carb passageways, the bowls filled nicely. But the engine still refused to start, instead backfiring dramatically out the exhaust system, which was immersed in a washtub, and plastering my house with premix-tinted water.

Fearing a sheared flywheel key, I checked the ignition timing, which was way off. (Fortunately, adjusting the timing required only fine-tuning the distributor linkage.) After more trials, I learned the engine likes lots of throttle to start, and then it caught and idled fine in its little private hot tub. Things were looking good.

A Classic Boat and Two Classic Motorcycles
Classic bikes perfectly complemented the classic Chrysler.Seth DeDoes

Bringing Bikes
Naturally, the Honda wouldn't run. A sulfated battery, a carburetor full of dodgy-looking chemical nodules, dark gooey oil in the crankcase, jammed control cables, and an inoperative speedometer all surfaced as I tinkered. A new battery made spark happen, but deeper problems lurked within the tiny Keihin carburetor. Here, every passageway that could become clogged with old gas residue or aluminum oxide was so plugged. Also, the slide was frozen in its bore. A long soak in carb cleaner followed by handwork with a pick and other tools got it done.

But my friend JG also needed a bike to ride. Happily, another friend came to the rescue by offering his restored 1970 Honda Trail 90 (aka CT90), with the provision that it return home undamaged. We were ready.

With one working outboard and two working bikes, I knew we had our opportunity. Into a new 2018 Ford F-150 turbodiesel’s bed went the two Hondas, and into the boat went two 6-gallon marine fuel tanks, an aluminum loading ramp, a surfboard, a Danforth fluke anchor and chain, two paddles, and dock and bow lines. Our riding gear, life jackets, fire extinguisher and flare gun, clothes and a cooler went inside the F-150, which, by the way, did a fine job hauling our entire vintage collection.

Escaping Los Angeles, I was relieved to find the boat and trailer towed beautifully. Before leaving, I’d replaced the bearings, added new Bearing Buddy protectors and marine grease, and had new Carlisle six-ply tires fitted to the 12-inch rims. Money well spent, because the trailer behaved perfectly over nearly 1,300 miles.

A Classic Boat and Two Classic Motorcycles
The bikes had to be rolled into the boat backward.Seth DeDoes

Fantasy-Reality
On a Friday morning in late summer, we made it to the lake, and it was about as deserted as deserted gets. A few old-timers were fishing, but otherwise all was quiet, with no PWC riders, wakeboarders or pontooners in sight. Just us odd ducks. The time had come to see if this old rattrap speedboat could be repurposed as an aqueous pickup.

A Classic Boat and Two Classic Motorcycles
With the foot pegs folded, both bikes were able to fit through the walk-through windshield area.Seth DeDoes

Hull and Inspiration
Weeks prior, I had reverse-engineered the bike-loading process, starting with how the bikes should be unloaded once we reached the far side of the lake. It required rolling the bikes into the boat backward, and that's what we did.

Right there in the dirt parking area above the launch ramp, I lowered the truck’s tailgate, positioned the aluminum ramp from the pickup bed onto the boat’s wide bow, and cinched it to the bow cleat with a tie-down strap. After untying the SL90, JG and I lifted the rear wheel onto the ramp and rolled it backward toward the boat. When the rear tire was about to drop over the bow, we climbed into the boat’s forward seating area, and each grabbed one handgrip and the saddle. We were able to first lower the 220-pound ­Honda’s tail end, and then its front end, slowly into the boat.

With its foot pegs folded, the Motosport 90 rolled aft through the walk-through windshield area until the taillight met the splash tray near the motor. While not harmful at rest, too much jostling in this position would certainly break the lens. As a workaround, we put a two-by-four under the rear tire and lifted the taillight just enough. Using the boat’s aft cleats, we secured the SL90 at its upper shock mounts, then added a third tie-down from the fork forward to one of the Chrysler’s windshield mounting posts. The SL90 held solid to this spot.

Encouraged, we repeated the operation with the Trail 90. We were ready to launch.

A Classic Boat and Two Classic Motorcycles
The cathedral hull both rode and handled well on plane.Seth DeDoes

Shake and Wake
Dear long-retired Chrysler engineers: Maybe it's symptomatic of this old engine, but did you know that at low revs, the Magnaforce 85 triple vibrates like a paint shaker full of claw hammers? As such, when advancing the throttle for the first time, I was as nervous as when lining up for a motorcycle race. Would the motor stumble and die, or shake itself off the transom? Or instead, would the strangely loaded hull nosedive underwater, or worse, roll over and sink? This was a gamble — and we all knew it.

But winner! Instead of disaster, the boat and motor worked together like a diazepam dream as the revs and speed built. Once in its sweet spot (over about 3,000 rpm), the three-cylinder engine smoothed out radically, and the cathedral hull both rode and handled well on plane, exactly as Chrysler had advertised 48 years ago. ­Eyeing the lake’s far shore, we passed an aluminum skiff and its fishermen, who eyed us suspiciously. I felt a surge of adrenaline — we were going to make it.

A Classic Boat and Two Classic Motorcycles
After crossing the lake, a session of beach riding, hill climbing, and racing side by side was on.Seth DeDoes

Happy Trails
After choosing a landing point in the sheltered cove, I throttled down the Chrysler, shifted into neutral, and then idled forward until that vaunted old cathedral hull nudged the gritty sand of the High Sierra. Unloading the bikes was the reverse of loading, with our aluminum ramp angled to the ground instead of the pickup bed.

We kick-started the bikes and launched into a session of beach riding, hill climbing, and racing side by side on the Jeep tracks. Soon I broke away on the SL90 to explore a mystery. Years ago, an old-timer at the lake had explained that at the end of the Jeep tracks, there was a narrow trail that wound toward the distant ­Sierra peaks. And that’s exactly what I went to find.

A Classic Boat and Two Classic Motorcycles
The High Sierra offered amazing views.Seth DeDoes

Lord knows I tried, riding to the absolute end of the Jeep tracks, scanning the ­surroundings 360 degrees, and then parking the little Motosport and climbing a rocky escarpment for a better perspective. But the alleged single-track wasn’t there — not that I could find, anyway. All that presented itself was hectares of forbidding rock, but you know what? It didn’t matter, because everything else had come perfectly to pass. I felt as excited as I had 10 long years ago, when I first stopped by the lake. Old dreams, and old boats, never die.