Record-breaking ARC for Rambler 88: all the secrets of a superboat

At 15:14:15 local time (19:14:15 UTC) yesterday, George David’s maxi Rambler 88 crossed the finish line in Rodney Bay, Saint Lucia, winning the ARC (Atlantic Rally for Cruisers) in real time and setting a new crossing record. To travel the approximately 3070 miles from Las Palmas de Gran Canaria to the Caribbean Rambler took 8 days, 6 hours, 29 minutes and 15 seconds (at an average of nearly 16 knots), beating the previous record, set last year by VOR70 Team Brunel, by just over an hour (a whisker, over that many miles).

A SPECIAL ROUTE
Although the winds were lighter than last year, the boat made the most of a small depression that formed in the middle of the Atlantic shortly after departure, which allowed the boat to sail on a more northerly course and then lean and accelerate more toward St. Lucia propelled by the trade winds. But the success is obviously also to be found in the fact that Rambler is one of the most innovative yachts around (in real, among others, it has also won the Rolex Middle Sea Race, the Volcano Race, the RORC 600 Caribbean and the Palermo-Montecarlo).

A SPECIAL BOAT
The boat, launched December 2014 at New England Boatworks in Rhode Island, is designed by Argentine architect Juan Kouyoumdjian and built entirely of carbon: 88 feet long, it has a hull with “powerful” shapes with the edges, characteristic of Kouyoumdian’s designs, running all along the boat, very pronounced. The boom has the special feature of being rotating, so that it adapts to the shape of the sail and reduces loads

A SPECIAL KEEL
The keel is canted, with a concavity in the hull of 20 centimeters around the keel pivot, and the elongated fin of the same size allow for the addition of a “compensation” (offset) of 15 cm to the bulb at 40 degrees of rotation. The positioning of the two daggerboards, very close to the centerline of the boat, turns out to be interesting. The absence of coffee grinders on board denotes how it is an automated boat to the max.

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XR-41 Gate, ORC reasons about it: there is an error in the VPP that needs to be corrected

A SPECIAL RUDDER
Very interesting then is the profile of the rudder blades, which was drawn with a line very similar to that of the fin of humpback whales. According to Kouyoumdjian this allows the moment of rudder stall to be postponed until laminar flow increases.

In fact, there is nothing worse than an unresponsive rudder when sailing launched at full speed, perhaps of lasco under gennaker or when at the start you have to get away from a jam of boats. In order to navigate quickly through the waves, the rudder is in fact often shaken violently, to separate the flow of water from the blades, and avoid stalling. The “waves” on the end of the rudder blade allow the upper profile of the blade to instead always sail in a steady flow of water.

RAMBLER’S NUMBERS
Overall length 27.00 m
Maximum beam 7.10 m
Draught 6.00 m
Tree height 41.47 m
Light displacement 22,890 kg
Upwind sail area 512/638 sq. m.
Sup. sail to the carriers 980 sq. m.
Sup. mainsail 318 sqm