Rovings April/May Issue 148

from Professional BoatBuilder magazine No. 148
Compiled by Dan Spurr

 A Million Ideas

The Harber 34C4Haber Yachts

Designed and built by Janusz Konkol, owner of Haber Yachts, in Poland, the Haber 34C4 (34′1″/10.4m) has sold well; attractive features include the pilothouse, shoal draft, and quality appointments. Inset—Several models have the optional patented four-centerboard configuration that allows the boats to sail a straight line without a hand on the helm or an autopilot.

One look at the portfolio of Janusz Konkol, a boat designer and builder in Poland, confirms that his mind runs in many directions at once: wooden boats, composite sailboats and motoryachts, center-console outboard boats, mahogany plywood classic runabouts à la Chris-Craft, GarWood, and Riva, traditional wood blocks for Tall Ships, composite and metal parts for automotive and other industries…. For 14 years Konkol’s Haber Yachts has supplied motorboats for RothBiltBoats in Yarmouth Port, Massachusetts. Haber Yachts employs about 50 people.

Haber Yachts powerboats
Mold for the RB24RothBiltBoats (ALL)

Top—Haber Yachts has built power­boats for RothBilt Boats of Yarmouth Port, Massachu­setts, for more than 14 years, under the direction of plant manager Piotr Wilk. Above—Prepping the mold for the RB24 (26.5′/8m) center-console powerboat.

Of the company’s five sail models, the largest, the Absol­went 900 (29′6″/9m) is a wooden sloop. The largest of the fiberglass models is the 34C4 (10.4m), available as a sloop or cutter. All have shoal draft and low-aspect Huari or gunter rigs with the masts stepped on tabernacles. Konkol’s aim is to offer boats suited for a myriad of service, from open ocean to lakes and canals, and for easy over-the-road transport. For the latter they generally have shallow draft, light displacement, and relatively narrow beam. The 800C4 described below meets Category C requirements as a sloop, and Category B with the extra ballast that comes with the cutter rig.

Of particular interest to sailors are three so-called self-steering models: the 660C4 (21′7″), 800C4 (26′/7.93m), and 34C4 (34′1″/10.4m). The C4 stands for the four centerboards in each model. Konkol writes that he was motivated to develop this concept—a standard centerline midships center­­board, another at the bow, and two more in the quarters—after a tense experience sailing with someone who knew next to nothing about handling a sailboat. The wind came up and Konkol’s friend was unable to hold a course while he, Konkol, attempted to go forward and drop the jib. Eventually they figured it out, but Konkol was determined to find a way to make a boat hold a course without relying on an autopilot, untrusting as he is of electronics.

The British magazine Practical Boat Owner (PBO), which has a reputation for fairly and rigorously testing sailboats on the water, spent a good deal of time on the 800C4 and published a detailed analysis of the boat’s handling with the four centerboards in its May 2009 issue. The writer came away impressed. First he addressed the offshore capability of the boat, stating that in severe conditions the “flush bottom” allows it to “slip sideways,” whereas a heavier-ballasted and deeper-draft yacht could trip and capsize. And speaking of capsize, the pilothouse prevents the boat from becoming stable upside down—in other words, there is no angle of vanishing stability (AVS).

The boat, which is also fitted with a conventional tiller and rudder, can be steered and even tacked by raising and lowering the correct centerboard. PBO’s reviewer wrote: “If you’re sailing upwind in gentle conditions under full sail with the bow board, main board and leeward stern board, you can tack simply by lifting the stern board: that moves the CLR [center of lateral resistance] forward so the boat rounds up and through the wind. Drop the new leeward board once you’ve completed the tack, and away you go—with no need to touch the tiller.”

Construction is polyester resin and hand-laid reinforcements—principally mat and woven roving—in a computerized humidity-and-temperature-controlled environment. Foam core is installed in some areas, but the hulls are largely solid. Hulls remain in the mold for a minimum of four days at a mini­mum temperature of 64°F (18°C), and at that temperature for four weeks before leaving the heated shop. Solid glass stringers are tabbed to the hulls of powerboats. Boats are tested in a water tank for watertightness and systems functions.

Consumer interest in the sailboats is focused mainly on the space and shelter of the pilothouse, shallow draft, construction quality, and, according to PBO, attention to detail. It’s unclear how many customers are lured by the intriguing capability of the four centerboards.

Principal dimensions of the 800C4: LOD 26′ (7.93m), LWL 24′8″ (7.53m), beam 8′2″ (2.5m), draft 1′10″–5′1″ (0.58m–1.8m), displacement 5,428 lbs (2,650 kg), ballast 1,323 lbs (600 kg), sail area 377 sq ft (35m2), D/L 164, SA/D 19.6.

Haber Yachts, 13-300 Nowe Miasto Lubawskie, ul. K. Makuszyńskiego 1, Poland, tel./fax +48 (0) 56 472 54 24, tel. +48 (0) 56 472 54 04, webiste


Composites at North Idaho College

HydroplaneTrevor Budge/North Idaho College

The Leland Unlimited Hydroplane Race Team has loaned a hydroplane to North Idaho College for composites technology students to splash and modify to instructor Trevor Budge’s specifications.

Students in the clean roomTrevor Budge/North Idaho College

In the layup, or clean, room, students learn infusion. The gray tanks are resin traps that prevent resin from entering the vacuum system. Each table has drops for air, electrical, and vacuum.

The first class in the Aerospace Composites Technology programEvan Moore

The first class in the Aerospace Composites Technology program gathers outside the hangar facility at the Coeur d’Alene Airport, in Hayden, Idaho.

You may recall reading in this column about Murdo Cameron, the ex-airplane pilot who decided he liked making flight simulators more than flying and teaching, and actually, liked messing around with advanced composites more than making flight simulators (“Composites Nut,” Professional BoatBuilder No. 128, page 14; “Infused With Enthusiasm,” PBB No. 144, page 12).

Murdo called recently to tell of North Idaho College’s (NIC) new Aerospace Composite Technology program in Hayden, in which he’s involved. Lest you wonder, there is a marine connection. Our earlier reports on Murdo were about infusing C-class hydroplane hulls and decks; he’s lent NIC boat molds to enable the students to get their hands on large parts. For more information on the program, Murdo referred us to composites instructor Trevor Budge.

The program, funded entirely by a $3 million grant from the Trade Adjustment Assistance Community College and Career Training Grants, implemented by the U.S. Department of Labor’s Employment and Training Administration, is intended to provide skilled technicians to the local aerospace industry, which includes Empire Airlines, several smaller aviation companies, and a number of composites firms that support them. Military veterans returning from overseas are a particular target group. The school estimates that the composites industry will need to fill more than 600 new jobs in the next two to three years. Graduates, of course, will be qualified to fabricate and repair composites in other fields, including marine.

Thirty-seven students enrolled in the first semester. Budge says about one-third are right out of high school, a third are hobbyists who want to learn more about working with composites, and another third are employed middle-aged individuals looking for better jobs.

Budge, who has an extensive background working for various composites companies in the United States and Australia—mainly building aircraft such as the all-carbon Turbine Legend that weighs 1,800 lbs (815 kg) and flies 400 knots—starts the students out on E-glass and polyester resin. He then works through vinylester and epoxy resins, and other reinforcements, including carbon fiber, and processes such as: hand layup (wet layup), vacuum-bagging, prepreg, and infusion. At the end of the first semester of the one-year program students’ final project was to make an object. This first year Budge says he saw all sorts of creative efforts, from bottle openers to tongs to a clock.

Skills taught in the program include: blueprint reading, technical math, writing, fabrication, trimming, assembly, damage removal repair, quality assurance, and NDI (non-destructive inspection).

In addition to the H-1 “pickle fork” hydroplane mold in the shop, Budge also has molds for a kayak, a skateboard, a wakeboard, and a model boat. The H-1 belongs to the Mark Evans racing team, which donated it to the school so students could splash it. Evans recently moved his team from Seattle to Coeur d’Alene, Idaho, and the city plans to resume high-speed racing on the lake there due to the success of last summer’s races, which drew tourists and money to the area. Interestingly, Burt Rutan of Scaled Composites (Mojave, California) retired and also moved to the area, so there’s a great deal of expertise in advanced composites residing in north Idaho these days.

North Idaho College, Aerospace Center of Excellence (ACE), 1845 Dakota Ave., Hayden, ID 83835 USA, tel. 208–625–2344, website


Four Times and Running

Principles of Yacht Design

The Fourth Edition of Principles of Yacht Design updates the now-classic text. Although powerboats are discussed, the emphasis is on how to design sailboats. Lars Larsson and Rolf E. Eliasson originally published the book in 1994, and a third author, Michal Orych, joins them in this new edition.

As yacht design evolves, thanks in part to the immense increases in computing power that enables designers to investigate multiple scenarios without ever building even a physical model, so also must books that inform us keep up to date. Such is the welcome case of Principles of Yacht Design, recently released in its Fourth Edition.

It was first published in 1994 by Lars Larsson, naval architect and professor of hydrodynamics at the Chalmers University of Technology, in Göteborg, Sweden. A member of America’s Cup teams for Sweden, Italy, and the U.S., he has written more than a 100 papers on computational fluid dynamics (CFD). In fact, he is chairman of a CFD company called FLOWTECH International, so is uniquely qualified to convey this sort of knowledge to amateur and professional yacht designers.

Larsson’s co-author then and now is Rolf Eliasson, an award-winning yacht designer (PBB’s design competition among them) who has more than 6,000 units built to his designs. Six of those he built himself, in steel, wood, and composites. A world-cruising sailor, Eliasson is a specialist in structures and computer techniques.

As one ages, it’s always good to bring in new blood, as Larsson and Eliasson did for this fourth edition: Michal Orych, a graduate of the Chalmers University of Technology in naval architecture, and CFD specialist at FLOWTECH.

In the introduction, the authors briefly mention many other texts on yacht design that have gone before, from Skene’s Elements of Yacht Design to books on the theory of sailing by C.A. Marchaj, and more recently, Aero-Hydrodynamics and the Performance of Sailing Yachts by Fabio Fossati. They conclude by saying that a successful manual on yacht design must “cover all aspects of yacht design” and be useful to amateurs and professionals. They don’t say it directly, but make it clear that their book is the only current text that satisfies these criteria, and they are probably correct.

Later the authors state that “yacht design is by its nature a quantitative process,” not qualitative, and what the designer needs to know, “as exactly as possible, is the minimum skin thickness and the least amount of lead needed in the keel for the yacht to be safe under all possible conditions.”

To provide the necessary information, many formulas are included in the book, but in deference to amateurs who might find them daunting, they are included with the many figures. Further, all the math is “of the algebraic type,” understandable to anyone with a secondary school education; no higher math such as calculus has been included.

As with previous editions, a notional yacht serves as an example throughout the design process. The YD-40 has evolved into the YD-41, a modern racer-cruiser for which is given the lines plan, rig, general arrangement, and computed values.

Powerboats are discussed throughout the book, but it’s clear that the authors are more interested in sail.

In addition, they include the results of recent research so that the knowledge is as current as possible, and indispensably collected in one place.

Despite the acknowledged importance of computers, the book begins with a presentation of basic manual skills for drawing on film, utilizing splines, ducks, curved templates, pencils, and erasers. En route to the final chapter titled Design Evaluation, with sections on towing tanks, wind tunnels, CFD, and VPP (velocity prediction program), every aspect of yacht design is dealt with in easy-to-read English.

From Froude to Gerritsma and Keuning, Simpson to Savitsky, it’s all here. Clear, concise, and comprehensive in 352 pages. $60. International Marine/McGraw-Hill Education, website


Carderock Upgrades Test Tank

The wavemaker

Bird’s-eye view of the wavemaker in action at Carderock’s upgraded Maneuvering and Seakeeping (MASK) basin.

Cutting the ribbon to open the Harold E. Saunders MASK basin facilityNSWC Carderock Division (BOTH)

Cutting the ribbon at the December 19, 2013, ceremony to open the Harold E. Saunders MASK basin facility are, left to right, Naval Surface Warfare Center (NSWC), Carderock Division, Naval Architecture & Engineering Department head, Jon Etxegoien; NSWC Commander, Rear Adm. Lawrence Creevy; keynote speaker, Dr. John Holdren, assistant to the President for science and technology, director of the White House Office of Science and Technology Policy, and co-chair of the President’s Council of Advisors on Science and Technology (PCAST); NSWC, Carderock Division Commander Capt. Richard Blank; and NSWC, Carderock Division Technical Director Dr. Joseph Arcano.

The U.S. Navy’s Naval Surface Warfare Center (NSWC) Carderock Division in West Bethesda, Maryland, recently celebrated the reopening of its Maneuvering and Seakeeping Basin (MASK) after numerous upgrades were performed. Built in 1962 to measure the performance of ship scale models, the basin is 360′ long and 240′ wide (110m and 73m) and holds about 12 million gallons (45,424,941 l) of water.

According to NSWC Carderock’s press release: “During the six-year upgrade, Carderock replaced the original pneumatic wavemaking system in the MASK with 216 individually controlled electro-mechanical wave-boards that significantly enhance the capability to create a precise wave environment. The new technology, demonstrated during the ceremony, provides the Navy with an unprecedented capability to create extreme, realistic ocean environments inside of the facility. Scale models up to 30 feet [9.1m] in length can be tested in the MASK in order to predict the full-scale performance of ships in the open ocean.”

Keynote speaker Dr. John Holdren, assistant to the President for science and technology and director of the White House Office of Science and Technology Policy, said, “As I marvel at this triumph of naval engineering and naval architecture, it is gratifying to see that once again the Navy is demonstrating its long-term commitment to science, engineering, and innovation.”

Carderock’s staff of 3,600 includes engineers, scientists, and technicians, headquartered in Maryland and with stations around the U.S. and Bahamas.

Naval Surface Warfare Center, Carderock Division, 9500 MacArthur Blvd., West Bethesda, MD USA 20817–5700, tel. 301–227–2307, website


Chesapeake Powerboat Symposium

Chesapeake Power Boat Symposium logoThe fourth Chesapeake Powerboat Symposium will be held June 23–24 at St. John’s College, Annapolis, Maryland. Sponsors are the Society of Naval Architects & Marine Engineers (in particular, the Chesapeake Section), CDI Marine, Stevens Institute of Technology, and Professional Boat­Builder magazine. The event is held every other year; previous symposia were in 2008, 2010, and 2012. A call for papers was issued in January 2013 for all topics: construction, materials and fabrication, structural mechanics, failure analysis and repair, modeling and simulation, tank-testing, software, propulsion systems, and human factors in control of high-performance boats.

Organizer John Hoyt III says he hopes to add several new features this year, the first of which will be inviting “companies to set up small booths in the lobby to advertise their capabilities and products.” Secondly, the Combatant Craft Department will conduct a 90-minute workshop on how the U.S. Navy processes acceleration data.

Previous symposia have been very stimulating. We reported on some of the papers presented at the first one, in “First Chesapeake Powerboat Symposium,” PBB No. 116, including “Regarding Small Craft Seakeeping” and another on vertical accelerations by Dean Schleicher; a “Discussion of Planing Boat Designs” by David Stimson of Boothbay Harbor Shipyard; “A Parametric Study of Dynaplane-Type Planing Motorboats” by the aforementioned John Hoyt and Eugene Clement; “Computational Design Tools for High-Performance Craft”; and “Development of a Performance Test Protocol for Small Powerboats,” by Richard Akers, Clifford Goudey, and Robert MacNeill.

Other all-stars attending included Donald L. Blount, Raju Datla and Snkanth Syamsundar from Stevens Institute of Technology, Paul Bieker, Christopher Barry, and Frank DeBord. During breaks attendees can enjoy coffee and donuts, and lunch with the speakers.

We hope to see you there! Send abstracts to either Ed Lewandowski at or John G. Hoyt III at More information is available at


Dustless Blasting

Dustles Blasting removing paint
Dustles blasting on running gearDustless Blasting (BOTH)

Recycled bottle glass removes bottom paint in this system from Dustless Blasting. The company says it took less than three hours to clean this 43′ (10.7m) motor­yacht, including the running gear (above). A small amount of water blasted with the media eliminates dust.

That’s right. It’s the name of the company: Dustless Blasting. Over the years, you may have used various media for pressure-cleaning the bottoms of boats. Similarly, sand, walnut shells, corncobs, dry ice, baking soda, and potassium sulfate are a few of the media employed for pressurecleaning in various industries—from food service to log homes and graffiti removal. All are shot in a stream against the targeted surface under high pressure.

Glass is yet another effective media for cleaning; Dustless Blasting uses recycled bottle glass and a small amount of water—15% of a conventional power washer—so that the media residue and bottom paint are contained and fall to the ground. No vertical containment like plastic sheeting is necessary, only a plastic ground cover that is folded up after the job is done, and disposed of in an environmentally correct way.

Dustless Blasting’s website has several videos of boat bottoms being blasted, saying that the old antifouling paint on a 35′ (10.7m) motoryacht’s bottom can be completely removed in less than three hours; and that includes time spent on the running gear (propellers, shafts, and struts). There is some operator skill involved, of course, but it’s not rocket science. Pressure is adjustable and critical to a competent, efficient, nondestructive job.

Dustless Blasting, 5711 Schumler Rd., Houston, TX 77048 USA, tel. 800–727–5707, fax 713–868–8041, website

Crossing the Bar

Since the last edition of the magazine, several notable figures in the world of boats have died.

Warren Luhrs, founder of Hunter Marine, builder of popular cruising sailboats, died last September 18. He and his brother John Luhrs were born into a family of boatbuilders in Morgan, New Jersey. Their father, Henry Luhrs, began building mahogany runabouts under the name Sea Skiffs in the early 1950s. After being sold in 1965 and bought back in 1981, Sea Skiffs joined the group formed by son Warren that included Silverton, Mainship, and Hunter. Warren Luhrs took up singlehanded ocean racing, setting a record aboard Thursday’s Child in 1989 for the fastest passage in a monohull for the New York to San Francisco run, eclipsing by eight days the clipper ship Flying Cloud’s time of 89 days.

Guy Couach, who founded Guy Couach Shipyard in 1962, died January 10 at the age of 88. Today, Couach Yachts, based in Gujan-Mestras, France, builds luxury motoryachts in the 20m–50m (66′–164′) range, all in composites. His ancestor Albert Couach is said to have built the world’s first marine engines.

Elbert S. “Mack” Maloney, author of many editions of Chapman Piloting & Seamanship and Dutton’s Navigation and Piloting, died January 6 in Pompano Beach, Florida, at the age of 94. Maloney served in the U.S. Marine Corps, retiring in 1964, after which he took a job with Chapman, and later assumed responsibility for updating the classic guide to boat handling, seamanship, and navigation. He also wrote for Motor Boating & Sailing magazine, and served in various positions with the U.S. Power Squadron and U.S. Coast Guard Auxiliary.

Yacht surveyor John C. “Jack” Hornor died last October 1 in Centreville, Maryland, at the age of 68. He earned a degree in business administration from the State University of New York, and studied yacht design at the Westlawn Institute of Marine Technology. An avid sailor, he wrote boat reviews for public consumption, and was active in the American Boat & Yacht Council, most recently serving as Chairman of the Board. According to one obituary, Hornor was “project naval architect and surveyor for the restoration of the 113-year-old steam tug Baltimore, which is docked at the Baltimore Museum of Industry.” He was also a regular presenter of IBEX technical seminars focused on yacht design and surveying.

The end.