Like many people around the world, Mercury Marine’s Steve Fleming was paying close attention to the mid-April rescue efforts on the South Korean ferry Sewol. The ferry had sunk but there was still hope that people might be alive within air pockets inside the vessel.
Fleming’s interest was more than just curiosity or sympathy for the victims. Wind, waves and currents worked against rescue attempts making it hard for boats to remain over the sunken ferry. “They kept saying that currents and conditions were horrible,” said Fleming. “I thought it was a perfect opportunity to employ the Skyhook system.”
Skyhook is a dynamic-positioning option that can be added to Mercury’s Joystick Piloting system for outboards. “It uses a GPS satellite to park a boat in a specification location and stay there,” said Fleming. “You can stay within a few feet of where you put it, no matter what the current or wind is.”
He figures that the biggest benefit of having Joystick Piloting is the ability to use the Skyhook system.
Though Mercury donated some items to the Sewol rescue effort, Fleming said he couldn’t get a Skyhook-equipped boat there. “It just took too long because I didn’t have anything within a couple thousand miles. But that would have been a perfect opportunity to show its search-and-rescue ability.”
The Skyhook-Joystick Piloting system works only with dual Mercury 250-hp and 300-hp Verado outboards. These are not after-market bolt-on systems. They are built into new outboards that are designed to be joystick-controlled.
It’s often difficult getting new systems accepted into the workboat market where companies and government agencies tend to go with what they know. That seems to be the case for joystick controls that have been embraced in the recreational market but not in the workboat field.
Roger Fleck at Moose Boats in Petaluma, Calif., said the diesel/waterjet-powered boats they build use “joystick controls almost exclusively, but not on outboards. We haven’t been involved with them.”
He attributes the reluctance to use joystick controls with outboards to the fact that “they haven’t been around that long. People are more comfortable driving outboards in a conventional way.” Whereas a waterjet-powered boat is an “unusual boat when you first approach it, so the joystick is a way to help introduce you to the jet.”
Scott Petersen at Safe Boats International in Bremerton, Wash., hasn’t had a lot of requests for either Mercury’s outboard Joystick Piloting or, for that matter, Yamaha’s Helm Master, a similar system.
He describes the concept “as really cool.” However, if a pleasure boat might be used 100 or 150 hours in a year, government and municipal agencies often use their boats 1,500 to 2,000 hours a year. “A lot of time agencies are a little skeptical until the technology is proven out.”
Peterson describes U.S. Customs operators “as being able to stick a boat in a shoebox in a crosswind” with traditional controls. “It’s what they do for a living. They don’t think the risk [of new technology] is worth the gain. For civilians, it’s a nice thing to have because you look like a hero when you come into the dock.”
Still, Petersen thinks joystick controls in workboat applications will eventually become more mainstream.
BIG POWER OPTION
Another outboard technology that’s having trouble gaining traction in the workboat market is Seven Marine’s 557. That’s 557 horsepower, the most powerful outboard available, with a ZF Marine transmission and a computer-controlled wet clutch sitting below a 6.2-liter General Motors aluminum block. It puts out 557 hp at 5,400 rpm.
Admittedly, the pleasure boat market was the original target for the 557 but there’s been interest in the workboat market, said Seven Marine’s Brian Davis. Still, he admitted, it will take the workboat market “a while to understand the product.”
Davis said that the only workboat currently using the outboard is a 50', 13-ton boat with a pair of 557s that replaced triple outboards. It’s been operating at an undisclosed location outside the U.S. since July for patrol and coastal protection.
By replacing triple outboards, the operator has improved fuel economy by 18% when operating at a 32-knot cruise speed, he said. The boat is capable of 50 knots.
In general, Davis said by using twin 557s the operator has a “10 percent top speed advantage and 20 percent better cruise economy at what we call high-speed cruise, versus conventional 300-hp triples. But go to traditional cruise speeds and we’ll be similar to triple 300s.”
Peterson said he’s very intrigued by the 557. “The GM engine is a proven source.” In a case where twin 557s would replace triples, he said a “200, 250-hp V-6 gear case at 70 mph creates about 390 pounds of drag. So where you can reduce drag, that’s a link to improved performance, though the hole shot might be less because you have less blade surface and less thrust.”
Despite the potential for improved efficiency, Peterson said customers have not purchased 557s, only asked questions about them.
Though most of the boats built at Moose are waterjet powered, outboards have advantages, especially for operators with a fleet of boats. “If you do have downtime, you can replace an outboard pretty quickly,” Fleck said, “as opposed to putting it out of commission to put a new diesel in.”
And there’s the money issue. Fleck said a pair of 350-hp Yamaha outboards can be purchased for $50,000. “You spend almost that much for one diesel engine, with no jet attached, and you still have exhaust, electrical and drive shafts. That $50,000, it’s complete, props and all.”
An outboard probably provides a little more speed than a waterjet but isn’t as maneuverable. A waterjet has advantages in shallow water because it’s not hanging below the hull, like an outboard’s lower unit.
However, as Peterson observed, when running in deep, rough water, “operating a waterjet can be a challenge. It just barely has to leave the water to start cavitating, whereas an outboard’s prop is less likely to lose momentum and bite.”
Some of the larger outboards are also a lot more reliable than in the past. “The new 4-strokes have gotten pretty darn dependable,” he said. “In the old two-stroke days, we’d all be dancing around if we got 1,000 hours. Now it’s not uncommon for a 4-stroke to get five, six, 7,000 hours. So they are quite a bit more cost effective.”
The newer outboards are also easier to repair then earlier models. For example, Peterson said, if government agencies that have limited mechanical capabilities can follow good instructions it’s easy to swap a motor out properly. The boat’s not tied up for a long time, as would be the case if a waterjet’s diesel had to be torn apart.
When it comes time to purchase an outboard, Petersen’s advice is not to be wedded to a single brand. “You have to go model to model. Mercury’s new 150 is kind of leading the pack in that category, where Yamaha builds a beautiful 300.”
And pay attention to service issues. “Logistically you want talented support with spare parts and mechanics close by. It’s not really driven by brand.”