65 — By Capt. Ken Kreisler
— February 2000
Going the Distance
|Arneson Drives propel the Pershing 65 to new heights of speed and luxury.|
"It was blowing pretty hard across the Stream last night," said Reg Corbett, project manager for Ferretti/Pershing of America as Darren Datson, Pershing’s stateside factory rep, eased the electronic Twin Disc EC200 Power Commander controls forward. I was seated in the double bench to port of the boat’s air-conditioned helm. Through the extra-large windows all around, including those in the massive stainless steel sliding door aft, I could readily see that the three- to four-foot chop outside of Fort Lauderdale’s Everglades Inlet ran from the edge of the Gulf Stream all the way to the beach.
In response to Datson’s move, the twin 1,420-hp Caterpillar 3412E diesels nestled way aft responded immediately as the familiar high-pitched turbo whine kicked in and the tachs approached 1400 rpm. As more power was delivered, he nosed the 65’s bow around to the north on our way to Palm Beach. We were now beam to the seas. But besides 2,840 horsepower, a pair of five-blade Nibral props, and a deep-V running bottom with 16 degrees of deadrise aft, the Pershing 65 had another piece of armament with which to meet these seas: a pair of Arneson #14 surface-piercing drives.
For those of you uninformed about the Arneson surface-piercing drive, let me explain its operation. It’s designed to place only the bottom half of the propeller, which produces thrust, in the water while the boat is on plane. The top half, which only produces drag, is out of the water. While initially developed for racing and high-performance vessels, surface drives have other advantages. Because they are mounted abaft the transom–extending as much as 10 feet–and pivot to either side like a stern drive, they improve steering response. The props are not under the boat, and this allows for effectively unrestricted prop diameters and reduces vibration, plus eliminates the need for rudders and reduces draft. In addition, the drives adjust vertically to allow the helmsman to adjust a boat’s trim to suit sea conditions.
All well and good on paper, but what does this mean to a luxurious 29-ton (34.5-ton, laden) 65-footer doing 43 mph through four-footers coming abeam? On this run, it meant a smooth, controlled, exciting ride. And that’s what you want a cruising boat to do: run well in deteriorated conditions. On other boats I’ve been on in similar conditions, I’ve noted considerably more slamming, jarring, and noise.
Once Datson had our drives at just the right attitude, and with the exception of the occasional big one, he rarely had to adjust his speed. "We’ve probably gotten about 10 knots more speed out of her with these drives than with conventional ones," he judged.
Upon reaching our destination, Datson had a chance to show off the 65’s maneuverability around the dock by first taking her in on a starboard-to approach with a swiftly running current on the bow and the wind to port. Using the Twin Disc’s trolling mode to reduce rpm, he positioned the 65 parallel to the dock, adjusted the trim angle down a bit, and put the wheel to port, starboard engine ahead, and port engine in neutral. With only a nudge from the bow thruster, our test boat made a controlled, soft landing. "Surface drives were once known for giving trouble during low-speed maneuvering," Datson told me. "But working the trolling valves with the drives and the thruster makes it easy in any kind of docking situation. You always have control."
From the dock, this sleek, low-profile boat, designed by Fulvio de Simoni, all but shouts, "Let’s go!" And while she more than proved she could do just that, her racy good looks are only the start. She possesses cruising amenities that will make any time spent traveling aboard comfortable and pleasing.
This article originally appeared in the January 2003 issue of Power & Motoryacht magazine.