Arneson Surface Drives
Arneson Surface Drives
(OP)
Greetings all...I would like to discuss the concept of surface drives and why Arneson is the "defacto" standard in the industry.
The concept is not really that hard to grasp, pipe the power straight to the prop, keep the prop half-in/half-out, and be able to steer. I got a quote for a pair of ASD drives, $26K A PIECE!!! Why the expense? Is it because there is no volume, and thus the HUGE mark up?
Has anyone seen surface drives for say, $10K per drive? Seems like the casting should be cheap, the bearings cheap, and a u-joint, cheap as well?
Can anyone help?
From a performance aspect, looks like this is the wave of the future. Why hasn't Mercruiser picked up on the idea?
Any thoughts appreciated.
The concept is not really that hard to grasp, pipe the power straight to the prop, keep the prop half-in/half-out, and be able to steer. I got a quote for a pair of ASD drives, $26K A PIECE!!! Why the expense? Is it because there is no volume, and thus the HUGE mark up?
Has anyone seen surface drives for say, $10K per drive? Seems like the casting should be cheap, the bearings cheap, and a u-joint, cheap as well?
Can anyone help?
From a performance aspect, looks like this is the wave of the future. Why hasn't Mercruiser picked up on the idea?
Any thoughts appreciated.





RE: Arneson Surface Drives
Mercruiser sells to volume markets, comprising boats that are typically too small to tolerate the axial length of an Arneson drive. They do have a joint venture with Cummins, Cummins Mercruiser Diesel, that sells into markets shared with Arneson. Maybe they have something on the back burner; I wouldn't know.
Since Mercruiser has been sued for swimmer deaths associated with unshrouded propellers on ordinary outboards, I assume their legal and PR departments would have a heart attack over any production plans for exposed projecting cleavers.
There are, or at least were, other surface piercing drive manufacturers. I'm a little fuzzy on the details, but I have been told that the technology is not universally magical.
Mike Halloran
Pembroke Pines, FL, USA
RE: Arneson Surface Drives
Mike is right, they are well made and have very small tolerances in the drive units for them to work properly. They may look simple but they have fairly big rams to raise, lower and steer the units and are very sensitive to incorrect adjustments. Add all that expensive low corrosion materials on the hydraulics and the electronic control units and it is easy to understand where the money goes.
But when you drive a boat like that at 50 knots you can understand how it seduces the wealthy.
By the way the props are for sale, they are brand new, have never been fitted on the boat and will probably sell for half the original cost.
RE: Arneson Surface Drives
RE: Arneson Surface Drives
There is another company...www.q-spd.com out of New Zealand that makes a similar setup.
What is really bothering me though, is that if the surface drives have lower drag, less moving parts, better efficiency, and comparable performance of a stern drive, then why aren't these drives going on boats of smaller, higher production volume, boats?
It seems to me, that the surfaces drives are a disruptive technology to the typical stern drives or outboard drives. Then I guess it's just a market demand problem. Until some higher volume boat companies switch over, they will remain very expensive and under used. Any comments would be appreciated.
RE: Arneson Surface Drives
The props have to be trimmed half in/ half out of the water. On a 60 footer, you probably don't have to do it often; on an 18 footer, you'd have to re-trim for every added passenger.
Two, with steering mechanisms, just flat don't fit on the transom of a reasonably trailerable boat.
They're not easily shipped or installed in one piece. Handling the individual mounts, cylinders, hydraulic lines, etc., takes time and skill that's not in the budget of a production boat.
They _look_ dangerous. Common sterndrives are no less dangerous, but have fewer noticeable edges and pinch points, especially above the waterline.
Mike Halloran
Pembroke Pines, FL, USA
RE: Arneson Surface Drives
You brought up some important points that I never thought of.
RE: Arneson Surface Drives
With regards to trimming it doesn't matter what size boat it is, you have to constantly trim them. The units must be fully down to start and gradually moved to optimum as the boat gets up on a plane.
Another problem is marine growth. In warm water, eg. South Florida, the props have to be cleaned by a diver every two weeks or boat speed suffers badly. If you leave it for 5 or 6 weeks you won't even get up on a plane.