It’s alive! Seven Marine has breathed life into its 557 outboard. The monster motor -- powered by 6.2 liters of supercharged Cadillac V8 -- was in the water at the 2012 Miami International Boat Show, and I got a ride. Ask me to describe the experience in a few words and I’d choose smooth and sophisticated. The V8 hums under the cowl, the ZF transmission shifts silently, and the powerband feel seamless. This is not the kind of motor that’s going to snarl and give you a kick in the pants when you drop the throttle. It’s more like a locomotive, churning away with unlimited, unabated thrust. Check it out:



We laid out the premise of the Seven Marine 557 when it debuted in a static display at the 2011 Miami show . Since then Seven Marine has put together several examples of the motor to use for development and endurance testing, which was conducted last summer and fall. Successful on-water testing generated support from investors that will finance the creation of production tooling and an assembly operation in suburban Milwaukee, Wis., with a goal of delivering the first motors to customers in June or July of this year. The motors will be built in batches of 25.

And there already are customers. Seven Marine President Rick Davis, the former head of advanced engineering at Mercury Marine, told me in Miami that the company has deposits for the first production batches of the 557 from both re-power customers and those working with a builder on a new boat. Davis says the projected retail price remains $70,000.


Seven Marine President Rick Davis (right) chats with Charles Plueddeman in front of the Seven Marine Miami booth.

Last year the Seven Marine 557 was the hit of the Miami show, its booth packed with people waiting to get a glimpse under the cowl, which was propped open like the hood on a car to reveal the big V8 and its polished stainless steel exhaust headers. The buzz is unabated this year. The company had a pair of motors -- one bright orange and the other bright green -- on display with clear plastic cowls to reveal more of the powerhead and other technical details, and the big motors were still causing excitement. In fact, my interview with Davis was constantly interrupted by people who had questions or just wanted to express their enthusiasm. One young man ran up to Davis and exclaimed, “This is the coolest thing I have ever seen. It is just so amazing that you have built these motors. I’ve got to get two of them for my 33.” Davis explained that he'd only need one 557-hp outboard. “Oh no, I’ve got to have two of them…” The guy was practically jumping up and down.

“The outboard motor is something everyone can relate to,” said Davis later. “And a V8 engine is uniquely American. Put them together and you really incite some passion. Which is why we’ve added details like the chrome outlets for the exhaust relief ports. They look like they came off a Corvette, and people love them.”

At $70,000 per engine, each 557 will be custom-painted to the customer’s taste.

At $70,000 per engine, each 557 will be custom-painted to the customer’s taste.

Owners will be able to personalize that passion. Each motor will be custom painted to the customer’s specification, and in the Seven display at Miami were center cowl panels for the engine in wild colors, logos, and a fish scale pattern. There will be other options, like a package of chrome-plated fasteners and stainless steel trim cylinders.

There was an eggshell-blue 557 motor on the transom of  the Sea Hunter Tournament 29 I used for a demo ride at Miami, which matches the boat’s hull striping and logo. This 29-foot 10-inch center console has a beam of 9 feet 10 inches and a max power rating of 600 hp. We ran 65 mph on a short blast up the channel. Sea Hunter performance specs report a top speed of 55.8 mph with twin Yamaha F250 motors, and 66.2 mph with twin Mercury Verado 300 motors. Sandy Ballou of Seven Marine, who joined me on board, told me that they have only had this boat for 10 days, and expect performance to improve with more prop testing.

The stated point of the Seven Marine 557 is to replace twin outboards with a single 557, or triples with a pair of 557 motors, gaining performance by reducing drag and the complexity of rigging and maintenance of multiple motors. But maybe the only reason to buy a $70,000 outboard is simply because you want to have one, or two, or three, of the coolest motors on the planet.

For more information, visit Seven Marine.

Written by: Charles Plueddeman
Charles Plueddeman is's outboard, trailer, and PWC expert. He is a former editor at Boating Magazine and contributor to many national publications since 1986.