April/May 2013 — Table of Contents
On the cover: This 31.2′ (9.5m) Boomeranger Special Ops C-3500 open RIB, powered by twin 300-hp Mercury Verado outboards, was the subject boat for a series of tests by the builder to determine the efficacy of two different models of shock-mitigating seats.
Story on page 52.
Photograph by Jaakko Pitkäjärvi/courtesy Boomeranger Boats.
26 The Hybrid Conundrum
by Nigel Calder
There is little objective data to help determine whether hybrid propulsion technology, serial or parallel, is worthwhile in marine applications. Recent research and on-the-water testing shed some light on the subject.
40 The Unknowable Lightness of Composites
by Richard Downs-Honey and Ginger Gardiner
Boatbuilders invest in optimized laminate design and fine-tuned
resin infusion to produce high-quality lightweight laminates, but
parts still end up heavier or lighter than intended. Why?
52 Practical Impact-Exposure Testing
by Jussi Mannerberg
To comply with the European Union’s 2002 Vibration Directive,
Boomeranger Boats, a RIB builder in Finland, tests shock-mitigating
seats to determine which will best reduce impacts on boat operators.
by Rob Mazza
The list of designer Bruce Kirby’s sailboats is formidable, headlined
by the enormously successful Laser, and including America’s Cup
contenders and a line of cruising sharpies.
4 Letters, Etc.
Readers comment on unsinkable boats; console design considerations; shock mitigation; owning component failure; and who’s who at Salthouse Boatbuilders.
compiled by Dan Spurr
Testing and innovation at Competition Composites; Jan Gougeon; Torqeedo goes big; Rockler router tables; a longboard with vacuum; George Cuthbertson on keel design; and Dyena’s acceleration recorder.
18 Best Practices
by Jim Moores
One yard owner complied a few basic lifting and blocking rules to prevent damage to vessels hauled and stored at his facilities.
80 Parting Shot
by Eric W. Sponberg
Faced with the market-driven ubiquity of modern sloops, the ketch is an increasingly rare sight in the catalogs of new production sailing yachts.
61 New Products and Processes
77 Classified Advertising