I have driven a few boats with surface drives some were Arenson Drives. My total time is much less than with outdrive boats. All my experiences with surface drives have been great but I think they remain a bit of a mystery to many. So rather than guess or speculate we asked Rik from Arneson to
answer a few questions.
PBN: What is a “Surface Drive”?
Arneson. A “Surface Drive” by definition is any propulsion that operates at the surface of the water. Be that a swimmer’s hand, a paddle for a canoe, a paddle wheel for an old steam ship, up to an Outboard on a Catamaran, or a Bravo on a fast Catamaran, a MK#3,4,5,6 &8 and of course an Arneson Surface Drive. All of these devices are setup to or meant to be run at or ABOVE the water’s surface level. Some by several inches even.
PBN: Is positive trim available in a “Surface Drive”?
Arneson. No… Why? Well in order to gain the leverage of pushing the stern down and in turn lifting the nose of the boat up, a propeller must be submerged in the water when the drive is trimmed. At the surface however, once the drive units are trimmed upward there is nothing there to meet the propeller other than air. A propeller pushing against air will not lift the bow of a boat no matter how high one trims.
PBN: Are Arnesons difficult to dock?
Arneson. No, while the reactions might not happen as fast in some relations they will be faster in others and this is the same for any surface drive not just an Arneson. When comparing an Arneson to any other Surface Drive with the propellers on the same centerline the results will be the same .
PBN: Are Arneson Surface Drives more expensive than an comparably rated I/O?
Arneson: Quite the opposite. Comparing comparable power ratings and equipment between them, an Arneson Surface Drive is less expensive than an I/O alternative. Example: Take our Bravo Conversion Kit which is priced at $24,500.00 each. That price includes a Standoff box, External Hydraulic Steering Cylinders with fitting/hoses/thru hulls, a Trim Cylinder with fitting/hoses/thru hulls, Trim Pump, a “Tri Starter” Bell-housing, HD Drive Plate, Transmission, Oil Cooler, Shift Bracket, Drive Line, Rear Engine Mount, Indicator Mount, Mounting Hardware, The #7M Drive Unit and even Propeller Nut with Washer.
Compare what an upgraded I/O cost, add in drive showers, standoff boxes, helm units, transom assemblies, upgraded gimbals, upgraded helmets and don’t forget external steering and you will see a price that is much higher than what the Arneson Bravo Conversion Kit cost by several thousand dollars and another important fact is the Arneson comes with a warranty and does not cost the boater speed.
Likewise, on the larger ASD8 Drive Units, these are priced less than the cost of a new Mercury MK6 or MK8 and the Arneson ASD8 has a higher hp rating.
PBN: You mentioned speeds?
Arneson: Yes, on a typical Bravo Conversion, the boater sees a 10-15 mph increase in mid-range and top speed. Not a bad value when you get reliably and speed increase for a lesser cost and lower maintenance.
PBN: What is the biggest obstacle for Arnesons?
Arneson: Getting consumers to realize that if they have a good boat now, an Arneson will only make it better by enhancing the handling and increasing the boats speed safely which is what it’s all about. Speed is nothing without control.
People think that their boats design is unique, and while certain aspects are unique to each boat made, there are only so many ways someone can successfully make a 38′ V bottom with a 102″ beam and 24 degree deadrise bottom. Try drawing it out on a piece of paper, the constraints alone make them very very similar to one another. So it goes back to the statement, if you have already got a good running boat, the Arnesons are only going to make it better.
PBN: Do Arnesons only work on Catamarans?
Arneson: 98% of the Arneson sales are on V bottoms, yet we all read on the internet when someone one ask if they will work on a V someone incorrectly states they only work on a cat, then when a catamaran owner ask if they will work on a cat, some know it all with no experience states they only work on a V bottom. This probably the biggest obstacle as asked above is mis-information.
We have Arnesons successfully running on Straight bottom Cigarette’s, Stepped bottom Cigarette’s, Straight bottom Scarab’s, Stepped bottom Skater’s, as well as both Straight bottom and Stepped bottom Hustlers, Profiles, Donzi’s Fountains (also stepped and non stepped). There is no specific requirement for Arnesons to work on a particular boat other than it be a good boat to start with.
Same can be said for Catamaran’s. We have all the major makes of Catamarans successfully with Arnesons. Skater, MTI, Mystic and so on.
PBN: What about notched transoms?
Arneson: Simply put, if it’s a V bottom with a notched transom, and it’s a side by side application the notch will not be an issue as the notch ends at the engine center line of the standard 35″ which is a normal side by side.
On a stagger V bottom with a notch there will be a small filler panel made to fill in the area where the Arneson mounts only which is usually only a few inches tall; the entire notch does not have to be filled in.
PBN: What new items are coming out from Arneson?
Arneson: Currently we are in the process of designing a new Drop Box Arneson ASD8 with a quick change ratio in them, we have a new Stainless Steel Thrust Tube for the fixed trim BPM style drive units and we are designing a new drive for a single engine application.
PBN: Does an Arneson need to have a separate rudder and fixed drive units on Catamarans?
Arneson: Absolutely not and this stems from the past and once again mis information. Historically, there was no way to put a mechanical tie bar onto an Arneson for catamaran applications due to mounting and geometry constraints; however, with our newest designs those two issues have been eliminated and we can run a mechanical tie bar assembly on the Arneson Surface Drives installed upon catamarans without any stress nor mounting issues.
We of course can and do make an external rudder assembly as well as the vertical trim cylinders (bottle jacks) and we can fix the Arneson Surface Drives so that they do not steer, but we only do that if the customer desires it that way as what it can give it also takes away in the form of slow speed handling and docking and for a pleasure boat application that is to large of a proportion to have to give up especially when they don’t have to.