Drive system turns handling into a joy

The handily positioned joystick allows even a novice to steer the Rayglass 4000 sideways through the gap in the marina breakwater. Photo / Supplied

Joystick controls have been around for a few years but, until recently, no boatbuilder in this part of the world has fitted Mercury's Axius steering and manoeuvring system to a twin diesel stern-drive boat.

Most instead have been fitted to pod-driven boats, purpose-designed to be controlled by joysticks.

Perhaps not surprisingly, as the popularity of these systems has increased, so has the level of inquiry for them at top local boatbuilder Rayglass Boats.

Rayglass produces probably this country's top-selling 12m sports launch, the Rayglass Legend 4000 (50 have already been sold in the 4 years since the first one was released at the 2005 Hutchwilco New Zealand Boat Show).

However, because of the way the 4000 is designed, it is not possible to fit a pod-drive system in its engine bay. Luckily for the company and those wanting a 4000 and a joystick-controlled launch, Mercury's Axius system has provided the answer.

Axius is basically the same system that is used on Mercury's Zeus pod drives, adapted to work on a pair of stern drives instead. Using the same technology, the system independently controls the two lower units through a complex software program that translates the simple moves of a joystick into boat movement.

From Rayglass's point of view, the benefits are enormous: it can now offer a complete joystick-control package without having to make any alteration to the shape of the hull.

How well it works was demonstrated just before Christmas when Pacific Motoryacht editor Barry Thompson and I were invited to join Rayglass general manager Dave Larsen on the 50th Legend 4000.

We met Larsen at Half Moon Bay marina and found a 4000 powered by twin 320hp Cummins Mercruiser QSD diesels running through a pair of Bravo 3 legs. The difference in this case was that the two stern drives were not connected by a tie bar but set up to be completely independently articulated.

They were also connected to Mercury's popular Digital Throttle and Shift (DTS) controls and an electronic/hydraulic steering system. The result was a stern-driven boat as manoeuvrable as a pod-driven one.

Larsen first demonstrated the 4000's manoeuvrability by coming in sideways to the pontoon immediately inside the marina entrance so Thompson and I could disembark to take photos. There was no need to tie up, despite the reasonably blustery conditions, as he gently held the boat in position using the joystick.

Next he took the 4000 out through the marina entrance and back in again - sideways.

Once the photo session was complete, it was our turn. To say the Axius is easy to use is a bit like saying a glass of water is easy to drink. The system is predictable and intuitive.

One moves the vessel by pointing the joystick (a comfortably large, round knob placed conveniently to starboard immediately behind the throttles) in the direction one wants to go. The more one pushes in a particular direction, the faster one goes. There is no need to use the wheel or the throttles to turn the boat in its own length, to crab it sideways or to reverse around a corner.

Within just 15 or 20 minutes, I was so confident of the system I easily emulated Larsen's feat of moving the 12m 4000 sideways through the gap in the marina breakwater.

Such showmanship and manoeuvrability is, of course, only a small part of the story. The system allows virtually any member of the family to dock the boat in the tightest of marina berths, regardless of the prevailing conditions, with little practice.

It also means there is no need for a bow thruster: Axius is far more nimble and easier to use than a pair of conventional drives and a bow thruster could ever be.

The system can also come with several other nifty features. These are packaged as Axius Plus Piloting and include VesselView, Auto Heading, Auto Yaw and Skyhook.

VesselView provides the skipper with a wealth of useful engine and vessel information. It also includes Cruise Control to maintain a steady speed and a Touch Pad Troll function that automatically reduces engine RPM for trolling or operating in no-wake zones.

In Auto Heading mode, the joystick simply corrects the heading by 1-degree increments.

Advanced Auto Yaw Control uses the integrated GPS and electronic compass to hold the bow of the boat at a precise heading, regardless of conditions. Last but not least, Skyhook is an almost magical station-keeping function that holds the boat in a single spot and at the same heading, simply by the press of a button. Unaffected by wind or current, it would be an ideal feature to use when wanting to hold station over a fishing spot.

Such features come at a price. Those wanting an Axius system for their next 4000 should be prepared to pay about $28,000 more. However, they will save by not needing either a bow thruster or autopilot.

Check out Barry Thompson's report on the Axius system on Rayglass's 50th Legend 4000 in the January/February issue of Pacific Motoryacht magazine.