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Maintenance

Joystick System Add-On for Twin Diesels

Comfort And Joy

Keep the boat you have but give yourself
the gift of joystick control.

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Behind the helm, the Xenta VMA Plus has modules to send joystick commands to the various components. Boxes for port and starboard engines and transmissions and the bow thruster all connect to a main brain.
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The Xenta joystick can be placed pretty much wherever the owner wants it. Note its shape, which puts the guts of the unit above the mounting plate.
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In the engine room, Xenta components mounted on the forward bulkhead share joystick commands with the transmissions and throttle controls.
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A visual sensor mounted over each prop shaft reads the speed and direction of the shaft turn and feeds the information to the control system. Much of the system uses optic signaling rather than electrical pulses.

You love your boat. You’ve finally got it set up just so (and it’s taken a few years), with just enough of the add-ons to make it truly one of a kind—your boat. So it’s rather painful when you walk the docks in your marina and see other owners swinging into their slips—in new boats they have barely any experience on—with the greatest of ease. After all, you’ve worked hard to get your close-quarters maneuvering down. You’re confident and skilled, but you’re also experienced enough to know that if you tangle with a bad crosswind or current it can get dicey. What do those guys have that you don’t? A joystick control.

Joystick control has changed the game: It’s taken away that midafternoon moment when you’re enjoying your boat and the back of your mind fast-forwards to when you’ll pull into the dock—that’s when your chest gets a little tight. Joystick technology is changing all that, however. And now you don’t have to change your boat (as much as you think) to get it, thanks to the Xenta Vessel Maneuvering Assistant Plus (VMA Plus) system. 

Xenta VMA Plus is a joystick system that works in conjunction with a bow thruster and conventional twin-engine propulsion to provide the functionality of pods or jet-drive systems without a complete hull reconstruction and total repower. The system is electronic and uses the existing engines, transmissions, and thruster setup. The company that developed it formed a strategic partnership with Italian boatbuilder Azimut Benetti Group, granting exclusive access to the technology in exchange for a commitment to buy a certain number of systems. But that agreement has ended and now Xenta is available to other manufacturers to offer as original equipment or to yacht owners as an aftermarket refit. SkipperBud’s in Winthrop Harbor, Illinois, is distributing the system for aftermarket refits and as an option for boatbuilders.

“We’re excited about it,” says Bill Wood, service manager for SkipperBud’s, and no relation to this writer. “We think it’s going to take off if the OEMs jump on it like we think they will, because it’s a very cost-effective alternative to a pod-drive boat or some of the other joystick brands that are out there.”

The basic system is around $20,000 installed. That is not a small sum, but it’s considerably cheaper than reconstructing the aft half of your hull’s bottom to accommodate pods or buying a new boat. But of course, not every boat can use the basic system. 

Here’s how it works. The prospective buyer fills out a punch list, answering some questions about the boat, including detailed specifications for the engines, transmissions, bow thruster, and the boat’s capabilities, notably hull speed. The specs are sent to Italy, where the boat’s prospective system is outlined, including pricing. Other joystick systems, such as the ZF Joystick Maneuvering System and the Twin Disc Express Joystick System work with conventional propulsion systems, but they have very specific equipment needs. Xenta’s VMA Plus is designed to work with a diverse range of existing components, making it a good choice for refit projects. 

“Some cost more than others for [components from] Volvo, ZF, CAT, MAN engines—there’s so many different marine manufacturers for engines out there,” Wood says. “The Xenta factory sends us all [the control-box components and cables], with it already premade, and we go ahead and basically install it. Then we just have to do a sea trial to make sure all the parameters are set up properly.” So it’s a fairly simple installation.

“It is straightforward,” Wood continues. “Say you’ve got a boat with different electric controls for your bow thruster. You run a cord to where your bow thruster is. Xenta’s cord has the same end that is on the bow thruster, just like a T-fitting. You unplug the control cable to the thruster, you put the Xenta cable in line, you plug them both in. That’s done. Hardest thing to do is run the wires.” Because everything is premade, those wires are already a set length with the end connections installed. That means running the wires requires a bit of forethought—passing an end connection through a hole in a bulkhead is not always a simple task.

Some of the control boxes are installed at the helm, close to the throttle and shift levers and thruster controls, and some go in the engine room. The installation we saw, on a Sea Ray 58 Sedan Bridge, seemed very straightforward. The thinking part of this system happens at the factory, so it doesn’t have to happen in the bilge.

One interesting aspect of the installation was the sensor setup that tells the system about movement of the drive shafts. A piece of white tape wrapped around each prop shaft and marked with a black bar turned as the shaft did, while a photosensor mounted above the shaft was aimed at the tape. Based on the direction and frequency with which the black bar passed the photosensor, the system knew the shaft movement that resulted from its commands and adjusted throttle and shift accordingly.

After the install, a sea trial makes sure everything is functioning as it should. “We plug a laptop in when the boat hits the water, so we go through the settings and make sure that it’s right,” Wood says. “We make sure it’s set so the throttles don’t engage too fast and jerk the boat around. We basically tune it in.”

The system can work with a stern thruster as well, but it is not required. And some installations allow the user to set the system to use the bow thruster or not. When I test drove the Sea Ray 58 Sedan Bridge on a breezy day, I was impressed with the smooth engagement of the system. It had all the capabilities that pod systems offer—spinning the boat on its axis, walking sideways, responsive backing, and more. Another interesting aspect was the electronic anchoring system, which seemed very precise on the breezy day we drove the boat. The joystick control box has indicator lights that tell you if the system is working: If the electronic anchor is maneuvering the boat to keep her in the position you set, those lights let you know.

I asked the owner of the Sea Ray, Webb Bassick, about the decision process he followed to choose Xenta. As he puts it, docking was a “yelling” affair on some of his previous boats. But that’s all been changing slowly but surely. “With our 480 Sedan Bridge, things started to fall together,” he said. “With a bow thruster and twin diesels, docking was much easier, without yelling!”

The next boat got even better: The 58 Sedan Bridge also had a stern thruster. “You still had four different ‘sticks’ to work with (bow and stern thrusters and the two engine controls),” Bassick says. “And when the wind was blowing, things could get busy. But it was a challenge, and for me that made it fun.”

Hit pause on the fun for a moment—Bassick’s wife Kathy once asked him what he calls the $64,000 question: What would she do if something happened to him on the water and she had to bring the boat in? So they started on a training program. Kathy quickly learned how to move the boat about the lake. “But that wasn’t close enough—it wasn’t at the dock,” Bassick says. “So I started teaching her how to move about the harbor, using only the engine controls and thrusters. It was not intuitive, but she was doing okay as long as there was no wind, or waves, or other boats.”

Meanwhile, Bassick had been watching pod propulsion systems develop. And then friends purchased a new Azimut, equipped with a Xenta joystick. “It was then that I began to realize that it would be possible to have many of the advantages of a pod boat without having to buy a completely new one,” he said. “It made a world of difference and provided her with control, in the way she needed to have it.”

SkipperBud’s won the distributorship in the U.S. thanks to its experience with Xenta as an Azimut dealer. “It was a big hit with the Azimuts,” Wood says. “When one of our customers bought an Azimut, he knew it had a joystick but had never run it, and when we delivered the boat he used the stick on the sea trial. He just sat there and looked at us and said, ‘A monkey can drive this boat.’” And if it’s that easy to use, imagine what you could do with it on your boat.

Xenta Systems, +39 06 20 25 417; www.xentausa.com
SkipperBud’s, 888-334-6739; www.skipperbuds.com

Webb Bassick’s Sea Ray 58 Sedan Bridge, Private Reserve, plies the waters of Lake Superior before the Xenta installation.

This article originally appeared in the August 2012 issue of Power & Motoryacht magazine.

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