ATL Composites provides the precision pieces for the latest Roger Hill-designed powercat.
The product of her owners’ yachting experience and a dream of long-range cruising, “Omahu”, a 16m Roger Hill composite displacement hull powercat, is taking shape at Lifestyle Yachts in Pipiroa, New Zealand.
As Roger Hill explains “The hull shape is a development of our very efficient displacement form, but the styling is unique compared to other similar sized power cats we have done before. It is not a ‘cut and shut’ exercise using an existing similar sized design.”
Omahu is the vision of joint-owners, two Kiwi couples keen to experience long-range cruising around the South Pacific, exploring New Caledonia, Fiji, Tonga and Australia.
One of the owners had previously built a Roger Hill-designed 14.15-metre sailing cat, around 15 years ago, customised to his requirements at that time. The choice of building materials, methodology and designer informed his choice for the current project.
According to Roger, the brief was reasonably straight forward. “There were around 20 specific items”.
“Both owners are very experienced yachtsmen, in power and sailing boats, with ocean-going range as the primary requirement. Both are very practical people, so it wasn’t difficult to convert their thoughts and ideas into the design.”
Emphasis was on comfort, rather than speed, although, powered by twin Yanmar 6LY400 400hp engines, Omahu is calculated to achieve an impressive top speed of 26 knots.
The design needed space for two couples to live aboard along with storage required for long trips to remote destinations where fuel, water and food might not be readily available.
The design process involved relatively few challenges.
“You have probably heard about the ‘design spiral’, the process of starting with a ‘loose’ collection of info and data and compromise through the design journey this becomes tighter and tighter until the final result is signed off.
“This particular design does not have as much beam (5.6m) as I might normally have on a displacement power cat of this length, but this was related to the width of the marina berth. The upside of that slightly narrower beam, less transverse stability will be an improved motion; not such a quick roll period in a beam sea, says Hill.”
With her shallow draft of just over 1m, Omahu will be able to explore remote inlets and anchorages where other yachts may not be able to access.
Seeking strength, durability, light-weight and precision, Roger based the design of Omahu on construction using DuFLEX Composite panels from ATL Composites.
“ATL and I go back a long way,” recalls Roger. “The first DuFLEX kit we did was over 18 years ago, and we have done many since then in both power and sail.
The DuFLEX Building System offers builders a very high-quality panel and very precise accuracy, and for the client, an assurance of structural integrity. From a technical standpoint, Omahu is destined to have a dark blue hull which dictated the choice of foam core to be used in the hull and transom areas. A combination of Divinycell HP80 and HP100 foam cores, type approved by DNV-GL Maritime, were chosen for the DuFLEX Strip Planks used in these areas to provide elevated temperature and mechanical performance under the owners’ choice of a dark blue paint.
Engineered to survey standards by ATL Composites Engineering team, other DuFLEX Composite Panels components in Omahu include wing-deck, soles, girders, webs, bulkheads, longitudinal and interiors all supplied in CNC-Routed Kit Form with various core types and densities to suit the design loads in the vessel.