Fuel capacity on the Aretis is about 30 percent greater, yet the freshwater tankage is less than half of Arara's, a result of the vastly improved capabilities of today's watermakers. Both the old and new designs top out at just over 15 knots, but surprisingly, the new yachts, with their signicantly higher displacements, use only 18 percent more horsepower.The difference is modern propeller technology.
Then as now, draft was an issue, and that meant using the highest blade-area propellers to deliver the best efficiency while still minimizing diameter and thus draft.The old yacht spun four-blade Columbian Bronze "Mako" wheels, off-the-shelf workboat props that were not as finely finished as that era's alternative, Michigan Wheel "DynaQuad" props, but provided a higher blade-area ratio, meaning more square inches of blade surface for a given diameter.
The new yachts run Michigan Wheel props, but rather than DynaQuads, they are semi-custom five-blade wheels that provide both the necessary area and a slimmer, better-finished section shape. The result is vastly improved overall propulsive efficiency, meaning the new boats are carrying a lot more tonnage at the same speed for just a little more fuel burn.
While I don't have exact figures for this installation, improvements in efficiency, purely as a result of propeller availability and the resulting optimization, have been as much as 30 percent over the 30-year interval between these two Burger deliveries. Add to that the fact that diesel engine technology has also advanced, with modern engines delivering the same power for about 10 percent less fuel burn, and you have a remarkable savings in fuel consumption-maybe not enough to offset the rise in fuel costs, but a significant nod to the wallet and the environment as well.
Another significant difference between the old and new yachts is the layout of the interior arrangement. Where Arara's guest staterooms were aft of her engineroom, those on the Aretis are amidships, with the engineroom, and its concentrated heft, aft. This shifts the yacht's center of weight and thus the hull's center of buoyancy aft, allowing the new wider hulls to have forward hull sections that are just as fine as those of the older, narrower yacht. This keeps the entry angle at the waterline low, and assures a smoother, easier passage in a seaway. It also places the guest staterooms near the center of the yacht, where movement is the least pronounced.
There are four guest staterooms surrounding a central foyer on the lower deck: the after two with queen berths and the forward two with twins. The aft cabins are a bit larger, which means wider berths, larger showers, big hanging lockers, and a small desk for VIP guests. The forward cabins have twin berths, smaller lockers, and smaller showers, though they're still large enough to include a seat. Off the foyer to port is an over/under washer and dryer (another is in the crew quarters forward), and a Eurocave wine cooler with a 260-bottle capacity. To starboard is a sauna that includes high and low benches, and under the staircase on centerline is a bonded storage locker.