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Infringement Claims for Boat Hull Patent Do Not “Float” with Court

April 17, 2001

Decision icon Decision

Last Month at the Federal Circuit - May 2001

Judges: Plager (author), Newman, and Schall

In Schoell v. Regal Marine Industries, Inc., No. 99- 1511 (Fed. Cir. Apr. 17, 2001), the Federal Circuit affirmed the district court’s grant of SJ of noninfringement for Regal Marine Industries, Inc. (“Regal”).

Harry Schoell is the inventor of a boat hull for a planing boat patented under U.S. Patent No. 5,456,202 (“the ‘202 patent”). A planing boat’s hull is designed so that at speed, hydrodynamic forces lift the boat hull almost out of the water. Planing hulls generally have broad flat sections on the bottom of the hull that allow the boat to ride up and skim the top surface of the water. These flat sections take a hard pounding when the boat is driven at high speeds through rough water. A Vshaped hull has been widely adopted to help overcome this problem. Boats with V-shaped hulls perform well when planing, but become much more difficult to maneuver at slower speeds. The ‘202 patent claims a stepped offset between forward and aft hull sections, a V-shaped forward keel, and a generally flat aft keel. Schoell claims that this configuration provides both stability and maneuverability.

Regal manufactures a boat with a stepped-hull design referred to as the “FasTrac” design. The aft hull of Regal’s boat contains a V-shaped aft keel. The slope of the bottom sections join at a twelvedegree angle with the horizontal. And, the forward hull of Regal’s boat also has a V-shaped keel. The forward keel has a twelve-degree V shape at the offset that increases to a sharper angle as the keel extends toward the bow.

Schoell contends that the district court did not recognize that “generally flat” embraces configurations that are not perfectly flat. However, the district court acknowledged that a slightly concave aft keel as claimed in independent claim 10 is not completely flat. Furthermore, during the prosecution of this application, Schoell responded to the Examiner’s rejection of his initially filed claims that the reference the Examiner had cited showed no stepped offset and no generally flat keel. The cited reference described a V-shaped aft keel with an angle between twelve and eighteen degrees. Thus, not only did Schoell differentiate between a Vshaped keel and a generally flat keel, he essentially concluded that a twelve-degree V-shaped keel cannot be a generally flat keel as claimed in the ‘202 patent by virtue of his argument to the Examiner. Because Schoell so clearly distinguished between the two keel shapes, the Court reasoned that if Regal’s forward keel with a twelve-degree V shape satisfies the V-shape limitation, the aft keel also with a twelve-degree V shape, cannot satisfy the generally flat keel limitation. Thus, the Court concluded, Regal’s FasTrac hull does not literally infringe the claims of the ‘202 patent.

Schoell also argued that the claims do not require the forward keel to be V shaped along the entire length from the bow to the stepped offset. Schoell argued that the twelve-degree V-shaped aft keel can satisfy the generally flat limitation and the portion of the forward keel with a deeper V shape can satisfy the V-shape limitation. However, the Court rejected this argument, concluding that if Regal’s forward portion of the bow with its twelvedegree offset was V shaped, then the aft portion of the hull with a twelve-degree offset must also be V shaped and could not be considered generally flat.

Schoell also attempted to show that Regal’s boat infringed the ‘202 patent under the DOE by pointing to certain of Regal’s advertisements and sales documents, as well as alleged evidence of copying by Regal’s president. Schoell also submitted his own affidavit stating that testing he had performed on designs similar to those of Regal’s FasTrac hull confirmed his belief that Regal’s boat performs substantially the same function in substantially the same way to achieve substantially the same results as the claimed invention. The Court found this evidence to be wholly insufficient to support a finding of equivalents. At most, the Court concluded, Schoell’s evidence tended to show that Regal’s boat achieved similar performance. The Court noted that the DOE does not entitle a patentee to a jury trial on the basis of suspicion. It is a limited remedy available in special circumstances, the evidence for which is the responsibility of the proponent.