The automotive industry leads the way today when it comes to non-hull marine tech, but in 1931, it was the shipping industry that inspired Pierce-Arrow engineer Francis Davis to develop a power steering system for cars. Surprisingly, it took two decades after that before the first automotive hydraulic power steering system — the Hydraglide — made its commercial debut on the 1951 Chrysler Imperial.
It wasn’t long after that before power steering started appearing on recreational boats. Today, the auto industry (save British supercar builder McLaren) has again transitioned, this time to all-electric power steering systems, but the marine industry has stuck with hydraulic or mechanical steering for most recreational boats. That is, until Dometic and Yamaha unveiled all-electric steering systems that are now in the vanguard of kicking the hydraulic habit.
Why Change?
Hydraulic steering systems work well, but they are heavy, have a multitude of space-eating hoses and pumps, need quarts of steering fluid that have to be kept under constant pressure that can exceed 1,000 psi, require periodic maintenance, are time-consuming to install, and have a nasty tendency to leak.
Another annoying aspect is the loud whooshing sound that emanates from power steering systems whenever the wheel is turned even an inch. This mood-busting intrusion is more pronounced on pontoon-style boats, which typically house the steering pump in the helm console close to the skipper.
And because hydraulic systems must keep the fluid pressurized at all times when the ignition key is on, the pump is constantly running and drawing power from the charging system.
Electrical steering systems obviate the need for all of the aforementioned space-eaters. They only draw current when the wheel is turning, and they consume less power at all times.
Dometic’s Electric Power Steering System
Dometic is the world’s largest manufacturer of marine steering systems, which now include its Electronic Power Steering system. There’s a remote-mount steering actuator assembly that weighs just 15 pounds and mounts directly to the outboard in place of a hydraulic cylinder, using seven planetary rollers around a main center screw to convert rotational motion to linear motion. This inverted roller-screw design is most commonly used in motion and positioning systems in manufacturing and aerospace applications. A brushless DC motor powers the system, which Dometic says is largely maintenance-free aside from occasionally giving grease points some attention.
Dometic’s EPS system also adds functions to its electric helm, such as adjustability to the number of lock-to-lock wheel revolutions based on engine speed, and variable wheel resistance. The system is compatible with older versions of Dometic’s Optimus 360 Joystick Control, electronic helm and CANtrack color display. In the event of a system failure, a manual override procedure requires only the loosening of two support bracket pinch bolts in order to make it home.
The EPS system is designed to work on all major outboard brands, including new-generation V-6 and V-8 Mercury Verado engines that have integrated hydraulic steering systems.
So why add a steering system to an engine that already has an integrated steering system? For those with power-hungry boats equipped with cockpit air conditioning and 1,000-watt stereos and multiple multifunction displays, the energy savings that come with switching from hydraulic to electric power might make a difference.
In addition to outboards, Dometic also has EPS systems for inboards and sterndrives.
Yamaha’s Digital Electric Steering System
Yamaha’s Digital Electric Steering system is one of four upgrades available to those who have Digital Electric Control outboard models F150 and larger as part of the Helm Master EX system, which is the company’s latest and most useful iteration for controlling a boat. (Exceptions for this upgrade are older generation 3.3-liter F250 and F350A outboards.)
The Yamaha DES is also a true electrical system with no hydraulic pumps or lines that can make rigging a nightmare — especially when there’s a need for long, bendy runs to upper stations.
I got a chance to test DES firsthand on a Robalo 246 Cayman bay boat powered by a single Yamaha F300, and the system was superior to hydraulic steering in every way. The most impressive element of DES was its operational speed when used with a Helm Master EX joystick. Lock-to-lock travel took only a couple of seconds, allowing incredibly quick maneuvers in tight quarters when docking or when an uncooperative fish goes rogue during a fight.
The Price Point
A complete Dometic Optimus 360 system with joystick control, display and autopilot for twin engines can cost almost $20,000. A single-engine, no-joystick setup is more than $5,000. At the most recent International BoatBuilders’ Exhibition and Conference, Dometic unveiled an electric power-steering system for mechanical steering that costs $1,600. That last one is available to install on all existing SeaStar rack-and-pinion or rotary mechanical systems on outboards from 90 to 200 hp, and should be a huge boon to boaters with kids who love towables that require the driver to turn the wheel constantly.
Yamaha’s DES is part of the company’s Helm Master EX system and can be purchased as part of a bundle called the Full Maneuverability Package. That package, in a single-engine setup, also includes a joystick, tilt wheel, autopilot, harness and CL5 touchscreen display for $14,682.
The DES steering system also can be purchased as a standalone option for $4,310, with a fixed wheel and harness for a 20- to 26-foot, single-outboard boat.
As the automotive industry has proved, electric power steering systems are the wave of the future. They are cheaper to produce, require fewer man-hours to install, are lighter, require less maintenance and perform better. In the marine industry’s near future, they will be the rule, not the exception.
This article was originally published in the December 2020 issue.
