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12/17/2001
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Autoprop Makes David Myers's Nauticat Fly!
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| By:
Domenic Petrarca |
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David Myers, of Tuscaloosa Alabama, recently installed an Autoprop on his Nauticat 331, s/v “Kairos”. The Nauticat 331 is a Finnish pilothouse ketch, with an LOA of 34’ ,and LWL of 28’, is a sturdy, all around boat geared for short or long range cruising. Due to the relative size and draft, Kairos weighs somewhere around 18,000+ pounds, the Nauticat has an 88 horsepower Yanmar diesel, which when combined with the Autoprop’s superior thrust capabilities makes this boat fly!
Before installing the Autoprop, David used to drive Kairos at around 2800 RPM’s to achieve 7.5 knots, while now uses 2400 RPM for the same speed. At 2000 RPm with the new prop, the boat attains 6.2 knots of speed, a dramatic improvement from the 5 knots with his old prop! The most enjoyable difference, relates Mr. Myers, is in the light wind sailing. “With the old prop wind-milling, the wind had to be moving at over 10 knots to achieve even 3 knots; now she’ll get to 4.5 or 5 knots with the same speed, and actually SAIL with 5 to 6 knots of wind instead of drifting”. The top speed attained with the Autoprop was an incredible 8.3 knots, well over the hull speed of the Nauticats dimensioned 28’+ waterline.
This marriage was not entirely a perfect union at first. The first prop specified for this boat was for some reason inadequate in performance. The engine revolutions were held down quite a bit, which improperly loaded the engine, delivering poor thrust and smoke from the exhaust. Due to the self pitching characteristics of the Autoprop, it is difficult to match exactly the proper diameter and inherent pitch. However, after an initial sea trial, the problem was identified by Autoprop’s engineers, and amended in the form a new prop, which was exchanged under warranty. We are happy to report that the new prop was a huge success, with out too much trouble from the initial error. Thanks to David for his patience and confidence in the prop!
Kairos currently prowls the waters off the Gulf of Mexico, and is being outfitted for an extended cruise from the warm waters of the Bahamas, to the cool breezes of the upper East Coast. David Myers is a retired Learjet pilot, and is joined on his sailing adventures by his wife, who is currently on a “seabbatical”. Be sure to say hi, and wish them fair skies and following winds.
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