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Doing their level best

Water deflects off a Zipwake interceptor when it’s lowered into the water to level the  boat’s ride.

Water deflects off a Zipwake interceptor when it’s lowered into the water to level the boat’s ride.

Mike Walsh at Marine Services Corp. in Dalton, Ill., has been working with trim tabs and interceptor systems for years. Recently he installed the Zipwake dynamic trim-control system on two boats that couldn’t be more opposite in terms of design or intended use: a Grand Banks trawler and a Cruisers 45 Cantius.

The results, however, were the same.

“New boat owners don’t want to be trimming their boat all the time,” says Walsh, whose company offers full service and storage, as well as slips, on Lake Michigan. “You put it in auto mode, and it just works phenomenally. You’ve got new boaters buying 30- to 60-foot boats, and it’s not natural to them to know how to use them.”

Zipwake is the latest in a number of systems that “automatically” trim a boat. Many boaters have trouble using outboard motors, sterndrives or trim tabs to level a vessel’s ride. Like joysticks, which take the fear out of docking, automatic trim systems set a boat’s correct attitude when it’s running. (In part one of a two-part series on systems that smooth out a boat’s ride, we are covering trim tabs and interceptors. In a future issue, we’ll look at stabilizing systems.)

Zipwake and Humphree, both based in Sweden, have automatic systems that use interceptors to affect boat trim. Volvo Penta bought Humphree in spring 2016, and Volvo Penta introduced its Interceptor system the following November.

Olympic Engineering, a Greek company, makes HydroTab interceptors. GlobalTec Solutions in Maryland is the U.S. distributor.

Better known to boaters in the United States, Bennett Marine, Lenco Marine and LectroTab have automatic boat-leveling systems that get the job done with trim tabs.

How interceptors work

While trim tabs extend aft off the stern, interceptors are blade-like devices that mount on the transom and extend straight down to affect or level the ride. Because they have about five times less surface area than a comparable trim tab, interceptors create less drag, improve fuel efficiency and take less time to lower into the water.

Additionally, they create lift (tabs push down the bow or a side of the boat when lowered, but have no effect when raised out of the water). Zipwake and Humphree say interceptors work faster than trim tabs and provide a bigger boost in fuel economy.

“The average boater isn’t going to know what an interceptor is,” says Jamie Simmons, product manager for Imtra, the distributor for Zipwake in the United States. “It’s more about educating the end user and making them aware of the benefits they are going to be receiving.”

One of Humphree’s founders, Niclas Olofsson, sold his share of the company and later worked with partners to start Zipwake, where he is product manager.

“One of the main goals for Niclas with Zipwake was to not be expensive,” Simmons says. “His goal was to bring the same technology to the recreational market at an affordable price.”

Interceptors have been used on larger yachts, but Simmons says the sweet spot for Zipwake is typically 30 feet to 60 feet length overall. The system can be installed on new-build or existing boats and comes in four different starter kits.

Another thing that sets Zipwake and Volvo Penta interceptors apart is that they are control systems that manage a boat’s ride. They’re not merely trim components bolted to a boat’s stern.

“The biggest feature and benefit we hear from customers is the automatic roll control,” Simmons says. The brain of the Zipwake is the Smart Ride Controller, which contains an accelerometer, high-frequency antenna and gyroscopic sensors. The three systems work together to control the boat’s ride.

Zipwake offers four sizes of rectangular interceptors that range in length from 300mm (11.81 inches) to 750mm (29.54 inches). All are 115mm (4.53 inches) tall and about 23mm (0.9 inches) thick. They mount on the stern just inboard of the chines, similar to the way a trim tab would.

There are also four V-shaped interceptors that measure 450mm (17.72 inches) long and that range in depth or height from 161.5mm (6.36 inches) to 200.5mm (7.89 inches). They install on the V between the drives or propeller tunnels and cover a transom deadrise range of 11 to 24 degrees.

Rigging involves running wires between the interceptors and a distribution unit that’s installed inboard at the boat’s stern. A single I-BUS cable runs to the helm, to connect to the controller. All of these components are included in each of the four kits. Smaller boats get two interceptors; larger cruisers and heavier boats use four. Zipwake likes to see 30 percent of the transom covered by interceptors.

Once installed, the system powers up with the boat’s ignition. The user enters his boat’s parameters, and the Zipwake is ready to go. It requires no additional calibration. In automatic mode, the system is designed to control side-to-side motion, known as roll, and fore-to-aft movement, known as pitch.

The most basic Zipwake 300mm kit — with two interceptors, a distribution panel and controller — retails for $2,400. The price is about $4,500 for a kit with four interceptors for a 60- to 70-foot boat.

Zipwake interceptors counter fore and aft pitching and side to side rolling.

Zipwake interceptors counter fore and aft pitching and side to side rolling.

Volvo Penta

The Volvo Penta Interceptor System takes things up a notch with trim, list, ride, roll control and coordinated turn, all part of the company’s Active Ride Control. Auto Trim and List can correct a boat’s trim and level out a list. With Auto Trim, List and Coordinated Turn engaged, the system adjusts the list in a turn, based on a predetermined value, to keep the boat more upright during the maneuver. This reduces the feel of sideways forces on guests.

“The entire system can be programmed to interact with the vessel in a tailored manner, creating the desired boat behavior via custom settings,” says Jens Bering, vice president of marine sales for Volvo Penta of the Americas. “It is fully automatic — without the need of intervention from the operator — unless the operator chooses to make adjustments along the route.”

Humphree products had been considered more exotic and targeted to larger boats, but since the Volvo Penta acquisition, the company has expanded its range of interceptors with smaller 300mm and 450mm models. This gives the range six sizes up to 1,050mm, including 600mm, 750mm and 900mm. The Volvo Penta Interceptor System can be used on boats ranging from 25 to 90 feet length overall, including megayachts and commercial and military vessels.

Even though Volvo Penta makes inboards, sterndrives and pod drives, the interceptors can be used on outboards and water jets as well, says Kent Lundgren of Humphree, which still operates as an independent entity in Gothenburg, Sweden, also the home of Volvo Penta.

The Volvo Penta product is fully electrical and integrates into the Volvo Penta Electronic Vessel Control (EVC) platform. Brushless electric motors mounted on the inboard side of a boat’s transom control the interceptors. As with the Zipwake, the Volvo Penta/Humphree systems link to the helm with a single cable. Additionally, both companies manufacture the interceptors from composite materials to resist corrosion.

Automatic trim tabs

As Soundings Trade Only reported, Yamaha acquired Bennett Marine, which makes hydraulic and electrically powered trim tabs. Yamaha touts its Helm Master as a total boat control system, and Bennett has the AutoTrim Pro for its trim tabs, so a merging of the two systems may result from the acquisition.

“We’re very hopeful and excited about what that is going to bring to the table for us,” says Craig DeStefano, marketing director at Bennett Marine.

Bennett’s AutoTrim Pro has built-in position indicators.

Bennett’s AutoTrim Pro has built-in position indicators.

The latest version of AutoTrim Pro was launched last year and can be used with electric and hydraulic tabs in new-build or retrofit applications. It has manual modes for users who prefer to control trim themselves. The system automatically retracts the tabs when it senses that the boat is turning, and it does the same when the vessel decelerates.

The system includes a control unit that should be installed in a dry area, plus sensors and a touchpad that installs at the helm. The AutoTrim Pro control unit comes with built-in position indicators and four “favorite” settings that can be pre-programmed. Retail price for the AutoTrim Pro starts at $650.

Bennett’s primary trim-tab competition for the past few years has come from Lenco Marine, a company that has made only electrically powered tabs since its founding in 1986. Power Products acquired Lenco Marine in 2016.

The Lenco automatic leveling system is called Auto Glide, and the latest update, version 2.0, was scheduled to be released in August, according to national sales manager Johnny Thomerson.

“The product was initially designed for the consumer that had a 28-foot cruiser, and most of them that owned that boat had no idea how to operate their trim tabs,” he says. “This product was designed to take that out of their hands and do it automatically.”

Like the Bennett system, Lenco’s Auto Glide is sold through retailers and can be ordered with new boats. It is designed to work on all boats with all engines and uses GPS data to provide data to the Auto Glide control box. Each kit comes with the control unit plus the main wiring harness and required cables to connect to a boat’s GPS unit, network and/or standalone GPS antenna/receiver. The Deutsch connectors are waterproof.

The Auto Glide control unit has two “favorite” buttons, plus a hold setting, a manual mode and position indicators. When activated, the unit automatically lowers the tabs to reduce bow rise on takeoff and adjusts for the most efficient and comfortable ride. As with the Bennett system, when the boat goes into a turn, Auto Glide turns off.

A new product for Lenco, Hybrid Trim Tab Kits, could blur the lines between conventional tabs and interceptors. The tabs still mount on the stern like a conventional unit, but they only extend aft by 4 inches and are available in widths ranging from 18 to 30 inches with a down angle of about 42 degrees. They are available in 12- and 24-volt models and are for boats ranging from 30 to 44 feet length overall.

Whether a boat is equipped with interceptors or trim tabs, customers are looking for a system to take care of the boat’s trim.

“Every type of product is going this way to make it easier for the end user to drive his or her boat,” Simmons says. “It’s definitely the direction we’re going.”

Livorsi tabs for stepped hulls

To help stepped-bottom hull designs make the most of their efficiency and increased speed, Livorsi Marine developed stepped trim tabs.

Livorsi’s new tabs are designed for stepped hulls.

Livorsi’s new tabs are designed for stepped hulls.

The Livorsi 1150 tabs introduce air via grooves, channels and steps cut into the bottom. The manufacturer says the tabs reduce the friction that comes with regular tabs and can improve a boat’s fuel efficiency, compared with conventional units.

The 1150 tabs come with Livorsi’s 12-inch-wide transom plate, or they can be ordered with a 14-inch-wide plate to replace a Mercury Racing K-Plane trim tab. The 1150 is available in a fishtail or square trailing edge design.

If an owner decides the 1150 is not for him, it can be switched with Livorsi’s conventional 750, 850, 950 and 1050 tabs. The tabs accommodate boats from 20 to 60 feet length overall.

This article originally appeared in the May 2018 issue.



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