Mercury FourStroke, 4-hp, 1 cylinder, 0.123 L (7.5 ci) carbureted 2-valve pushrod (overhead valve)
Torqeedo Travel 1003, 520 Wh Li-Ion battery, 1000-watt input power/480-watt propulsive power (comparable to 3-hp gas engine in propulsive power and 4-hp in terms of thrust)
By Steven Bull
Advancements in power don’t always mean more horsepower. In fact, the portable power options these days are arguably just as impressive as the big outboards that have made big splashes—from Mercury’s 400-horsepower Verado to Yamaha’s 350-horsepower V8 outboard. Last year Yamaha launched the F2.5, a very light and spill-free designed outboard for tenders that had a lot of engineering advancement in that two-and-a-half horsepower package.
For this edition of PowerLines we figured we would take an in-depth, in-water look at a few options, so we strapped both a Torqeedo Travel 1003 and a 4-hp Mercury FourStroke on a small Zodiac.
The Zodiac is entirely inflatable, including the floor. It gets fairly rigid and is good as a hideaway tender on a smaller cruiser or to use for very sh
ort trips—you can read more details about the boat in our 2017 Test Issue of Boats&Places.
The Torqeedo T-1003 is an electric motor, so the first thing you need to get used to is gauging the power. You will see “equivalent horsepower” ratings with an electric engine and the T-1003 is the comparable to a 3-horsepower gas motor.
The main components of the T-1003 break down for easy travel and are intuitive to reassemble. In about two minutes the motor can be hanging on the back of the boat and ready to rock. Other than the power source and appearance, it’s the same concept as a gas-powered engine. It hooks on the transom the same way, has the same tiller control throttle and a kill-switch for safety, but it’s lighter, quieter and more environmentally friendly than gas-powered options.
Compared with the Torqeedo’s T-503 model, this has 60 percent more battery capacity and, thus, a greater range. You can extend that even further by hooking up solar charging, which can work during your voyage. As good as the batteries are, they also remain the primary downside. If you drain the battery, you’re looking at about seven hours to bring it up to full charge again.
There is a built-in computer with GPS that constantly updates the current battery life and range, so you should never find yourself adrift with dead batteries.
The only sound is a quiet, high-pitched whir when you crank the throttle fully open and the two-blade orange prop at the max that runs about 1,200 rpm.
Top speed was a flash of 5.5 miles per hour but that could have been wave assisted as 5.1 was more consistent.
The battery range varies depending on your speed from approximately 5 kilometres at full throttle to over 35 kilometres if going slowly (around 2 km/h). Full throttle, your running time is just over a half an hour, but going slowly you have multiple hours to toot around.
On the other end of the spectrum you have what, at a glance, is the mirror opposite. The Torqeedo is lighter and quieter, while the Mercury is heavier and louder. The Mercury is also about twice as fast as the Torqeedo and is actually quite green for an internal combustion motor. With a CARB Star rating of 3, the highest, it is considered “ultra-low emission.”
Even though it’s a mere one-percent of the horsepower of it’s 400R Verado cousin, this little Merc harnesses the decades of expertise of Mercury’s engineering advancements.
A one-cylinder, two-valve pushrod (overhead valve) design, this is carbureted and water-cooled with thermostat and features through-prop exhaust. That 7.5 cu. in (123cc) 4-horsepower whirs the prop around at a maximum rpm in the 4500-5500 range.
Our test boat was small and light with a surprisingly sturdy floor, so it took a little coaxing to get it to fall onto plane. I even had to lean as far forward as I could while holding the tiller throttle, but when I did we were rocking.
I was surprised at how fast we were able to go, peaking at 11 mph (17.7 km/h). It held the speed through turns nicely—not surprising given there wasn’t much strain once we got up on plane. This could have easily pushed a much larger boat around the bay.
It starts easily, too, and if it doesn’t start on the first pull, which it usually did for me, it was all but guaranteed on the second pull. That’s thanks to the automatic decompression that bleeds off cylinder pressure to reduce the force required to pull start.
While your range with the Torqeedo is dictated by battery charge, your Mercury range is dictated by fuel. To keep things ultra-compact you’ll want to use the integrated fuel tank but that’s only 0.3 gallons (1.1 litres) so you won’t be doing any epic voyages. But given the speeds, you can cover a lot of water so the range should be much higher at full throttle than the Torqeedo. Though I wasn’t going to run either of them dead to check.
There is also a standard fuel line hook-up should you want an external tank to expand your cruising range though doing so really negates the portability of a hang-it-and-run-it outboard set-up.
The main knock I have on the Mercury is that with oil and gas you have to be careful if trying to transport it full of fluids. They do a good job with it but it’s not 100% spill proof.
Though when I compare the specs of other portable options from Mercury I’m tempted to go for the 6-horsepower four-stroke. Sure it’s a little more money, but it’s 50% more horsepower at the exact same weight of 57 lbs. (26 kg) so you can use it on the same range of boats, including our little Zodiac.
Whether you want to embrace lightweight and quiet electrical power with Torqeedo or stick with better performance and range with a little more weight and noise with Mercury, there are some great advancements in small, portable power.