Published in: Saturday, 25 April 2009
Features > Marquis 500SB (Page 1/2)

Marquis 500SB

The Marquis 500 offers top notch styling in sports couple or sports bridge versions, and a triple Volvo IPS system for a speedy and fuel efficient ride

With its new series of 500 Sports Bridge and Sport Coupe models, Marquis Yachts offers a triple treat to boat owners. Sure, the American-built yachts exude styling sophistication that appeals to buyers worldwide, something not always easily achieved. And like the rest of the Marquis line, they’re certified to CE-Class A specifications, the European Union’s toughest standards category.

But more than this, the models incorporate the triple Volvo Penta IPS propulsion system. Volvo’s IPS systems have been around for a number of years, with the triple drive introduced in 2006. The IPS, owing to its forward-facing props and swivelling, horizontal drives, offers better speed, fuel efficiency and easy operation. And while other yachts have begun to incorporate the triple drive IPS, most are backfitting their boats with the triple IPS. Marquis has designed its 500 sports bridge with the IPS from the beginning.

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The IPS gets its improved efficiency because its forward-facing, counter-rotating propellers operate in undisturbed water as the boat moves forward. Efficiency is also due to the prop shafts being parallel to the boat bottom, not at a down angle, which means more power goes into moving the hull forward. And with the Electronic Vessel Control system, operators enjoy ease of use, with joystick control.

IPS engines “communicate” with one another and operate as a cohesive unit thanks to the EVC, Volvo Penta’s proprietary electronic platform, which makes systems more reliable and installation easier. According to Volvo Penta, these developments mean that compared to conventional inboards, IPS can boost top speed by up to 20 percent and cut fuel consumption by as much as 30 percent.

Marquis worked with Volvo Penta to tailor the running bottom for the 500 Sport Coupe and 500 Sport Bridge to maximise the benefits of the IPS setup. Marquis then gave that information to the Nuvolari-Lenard team, designers for the entire Marquis line, and Donald L. Blount & Associates, a naval architecture/marine engineering firm tapped for additional expertise. Even though IPS can be retrofitted to an existing hull form, Marquis Yachts felt this multi-team approach would take full advantage of the yacht’s performance and handling, ultimately making modifications based on all input.

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The end result is a boat with speed to match its style. Marquis wanted its 500 boats to have a cruising speed of at least 30 knots, something that a triple drive on a 50-footer can certainly deliver. According to Randy Peterson, head systems engineer for Genmar Yacht Group, Marquis’ parent company, the 500 would have needed twin 900-horsepower diesels to meet that kind of speed requirement. With a triple IPS engines, the same can be achieved with three 435-horsepower drives, for a total of 1305-horsepower, less than the 1800 of the twin diesels, and therefore certainly more efficient. Buyers can opt for a smaller triple set of engines at 370-horsepower each.

Sea-trial results conducted on the 500 Sport Coupe and 500 Sport Bridge bore that out. With the 500 Sport Bridge fitted with the higher-horsepower IPS, the engines consumed a total of 53 gallons per hour at the 3300-RPM cruise speed of 32 knots. At 35 knots, fuel consumption stood at 66 gallons per hour in one-foot chop, with winds of ten to 15 knots.

An added advantage of the IPS system is the underwater exhaust, as there’s no “station-wagon effect” with fumes, plus noise levels are dropped in the yacht’s cockpit, bridge, and saloon. During sea trials, the 500 Sports Bridge had recorded sound levels of 81 decibels at the helm at cruise speed, and 83 at top speed. “On a typical inboard, 81 would be reached by cruise speed, and wide-open throttle would be the upper 80s to low 90s,” Peterson explains. To put these numbers into perspective even further, the level of normal conversation is 60 decibels, city street traffic is 80, and a lawnmower is 90.

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The 500 offers additional space compared to a similar hull size, given that the overall engine size is actually decreased, with the three engines positioned farther aft thatn a traditional inboard diesel engine. This means more usable space in living areas. In addition, the middle engine is installed in a tunnel to keep its underwater gear at the same level as the outer engines, which permits draft to be a consistent 1.14 metres. On the interior, the 500 has a single-level living concept from Nuvolari-Lenard, which means everything on the main deck is on one level.

Throughout the interiors, the design team has sought to create a “global yacht concept”. Marquis clearly wants to offer a differentiated product, and they largely succeed. This concept involves the use of zebrano and cherry joinery as well as door hardware and other elements more commonly found on superyachts. You’ll also find two-metre headroom in the cabin.