When I was a kid learning the ropes through the pages of every fishing magazine I could get my hands on, marine propulsion systems were somewhat limited. If you were a boat manufacturer or owner repowering a serious sportfish destined to battle big seas, reliable single or twin diesel or gasoline inboard engines were the first viable options. The classic Robalo 29 is a good example. This brawny center console was propelled by twin inboards and built like a tank.
As we approached the 21st Century, mechanical engineering and computer-controlled technology advanced by leaps and bounds, and as a result power options grew. Someone somewhere finally came up with the brilliant idea of mounting two and then three outboard engines on the transom of a rugged offshore platform—outboard engines that were simultaneously experiencing rapid growth in both size and reliability. And while certainly important now, neither efficiency nor emissions were priority #1 at the time. No one seemed to care…the trendy outboard craze had spread like wildfire and 30-something-footers were winning tournaments everywhere racing to and from productive fishing grounds faster than ever before. It was clear the propulsion game had officially changed forever.
With inboard engines a complete upgrade of the entire powertrain would require serious manpower and depending on the exact configuration of the boat and motors, a serious investment in time and money.
Today, stroll the aisles at any boat show or flip the pages of any marine related magazine and you’ll see that propulsion systems have exploded beyond our wildest imaginations. Joystick controls…rotating pods…massive fishing machines approaching 50 feet in length powered by as many as five huge outboard engines all operating in perfect harmony. The outboard trend is expected to continue as engines proceed to grow in size, reliability and efficiency. Seven Marine recently introduced what may just be the biggest game changer yet—a 557HP outboard built around the reliability of a GM 8-cylinder supercharged automotive engine. Rumor has it a mid-50s convertible powered by four of these powerhouses is already in the works. Not sure if the rumor is true, but the end result would be worth seeing.
Why outboards? Lets start with a basic weight comparison. A Mercruiser 320HP inboard weighs 948 pounds. That’s the engine alone with no running gear. A Yamaha 350HP outboard weighs 804 pounds. While there are certainly many variables that need to be considered, less weight plus more horsepower typically equals greater speed and increased efficiency.
Maximum use of available square footage is another benefit, with outboards allowing designers to make good use of every square inch of below deck space. I opted to power our Strike 37 walk-around with triple Suzuki 300s equaling nearly the same horsepower as traditional twin diesels. Where there is usually a pair of 480 Yanmars, raise my bridge deck and you’ll find an expanded 490-gallon fuel tank, 60-gallon water tank, five battery bank system, and a plethora of mechanical and electrical components—all with room to spare. Yes, it’s three engines rather than two, but the outboards are much quieter than inboard diesels and the complete lack of fumes and smoke is truly appreciated.
Another advantage that stands out is how quick and easy it is to service and even replace outboard engines when compared to inboard power. Outboard owners often repower to upgrade from 2-stroke to 4-stroke technology. Some outboard owners upgrade for increased horsepower and speed, and some simply because the time has finally come to do so. I recently found myself in a similar predicament with an opportunity to upgrade our existing DF300s for a trio of 2011 powerhouses outfitted with a Lean Burn Control System. With the potential for a substantial savings in fuel costs, the decision was easy. At this point you may be wondering what my engines have to do with anything. The truth is that we’ve come full circle. You see, while we were anxious to repower, we weren’t anxious to lose valuable time on the water, so we put the team of mechanics at Outboard Specialties (fixboat.com) to the test. These guys are some of the best outboard engine mechanics in the business and the only team that has serviced my engines for nearly a decade. We asked if it was possible to swap triple outboard engines and have us back in the water in 24 hours?
With inboard engines a complete upgrade of the entire powertrain would require serious manpower and depending on the exact configuration of the boat and motors, a serious investment in time and money. Thanks to the outboards’ fully integrated systems, we hauled the boat at 7:00 a.m., the existing engines were disconnected and off the bracket at the boat yard by noon, and three new motors were uncrated and mounted by 4:00 p.m. After some fine tuning and testing by close of business, we were back in the water at 8:00 a.m. the following morning. In reality, the entire job was complete from A to Z in less than 12 hours.
Obviously, inboard engines continue to be the right choice in certain applications and I am certainly not trying to convince you otherwise. However, if it were apples for apples and the choice existed, with all of the benefits and ease of maintenance today’s outboard engines offer, they are certainly worth every bit of consideration. I wouldn’t trade mine in for the world…only for three new and improved ones.