Wilco Marsh Buggies v. Weeks Marine: Amphibious Vehicle Patent Invalidated After 975 Days
Wilco Marsh Buggies & Draglines, Inc. sued Weeks Marine over US Patent No. 6,918,801 covering amphibious vehicle technology. The Eastern District of Louisiana granted summary judgment for Weeks Marine, declaring claims 1–5 and 9–15 invalid for lack of novelty — and ordered Wilco to bear all costs.
Marsh vehicle patent invalidated on novelty grounds in Louisiana federal court
Wilco Marsh Buggies & Draglines, Inc. filed suit on November 18, 2020 in the U.S. District Court for the Eastern District of Louisiana (Case No. 2:20-cv-03135) against Weeks Marine, Inc., alleging infringement of U.S. Patent No. 6,918,801 (application no. US10/453795), which covers amphibious vehicle technology used in marsh and waterway environments. The action centred on whether Weeks Marine's operations fell within the scope of the asserted patent claims.
The case closed on July 21, 2023, when the court issued a final judgment following its ruling on Weeks Marine's Motion for Reconsideration and granting summary judgment in the defendant's favour. The court declared claims 1–5 and 9–15 of US6918801 each invalid for lack of novelty under 35 U.S.C. § 102, dismissed all of Wilco's claims with prejudice, and ordered Wilco to pay all costs. The recorded basis of termination is judgment on the merits for the defendant.
The 975-day duration suggests the litigation involved substantive procedural activity before reaching summary judgment, including at least one motion for reconsideration that preceded the final ruling. The invalidity finding on novelty grounds — rather than obviousness or claim construction alone — is a particularly decisive outcome, as it forecloses the asserted claims entirely. What drove the specific prior art basis for the § 102 determination, and whether Wilco pursued or will pursue any appeal, is not disclosed in the available record.
See Complete Case & Patent Analysis →Filing to Judgment on the merits for Defendant in 975 days
975 days from filing to final judgment — longer than the median patent case in this district
US6918801B2 — Amphibious marsh buggy vehicle technology
Any company designing, manufacturing, or operating amphibious marsh vehicles — including equipment used in dredging, wetland construction, coastal restoration, or pipeline installation — should assess their exposure to US6918801. While claims 1–5 and 9–15 have been judicially invalidated, the status of claims 6–8 is not resolved in this judgment. Additionally, Wilco may hold related continuation or family patents not asserted in this case. R&D teams developing next-generation amphibious or hybrid land-water vehicles should not assume the full patent family is neutralised.
Official order — verbatim text
The final judgment is unambiguous: the court invalidated claims 1–5 and 9–15 of US6918801 on § 102 novelty grounds following a successful motion for reconsideration that converted an earlier ruling into a summary judgment for Weeks Marine. The dismissal with prejudice forecloses any refiling of the same claims. The cost order against Wilco, while not constituting an attorney-fee award under § 285, adds financial consequence to the substantive defeat. The specific prior art that formed the basis of the § 102 anticipation finding is not reproduced in the available record.
Defendant wins on summary judgment: what the invalidity ruling means for both parties
Summary judgment on invalidity: the court's decisive finding
The court granted Weeks Marine's motion for summary judgment, finding no genuine dispute of material fact on the question of novelty. Under 35 U.S.C. § 102, a patent claim is invalid if the invention was anticipated by a single prior art reference disclosing every element. Declaring claims 1–5 and 9–15 invalid on this basis extinguishes those claims as a matter of law — not merely limiting their scope.
§ 102 anticipation — claims 1–5, 9–15 invalidatedWilco loses all asserted claims and bears full litigation costs
All of Wilco's claims were dismissed with prejudice, and the court ordered Wilco to pay all costs of the matter. The invalidity finding means the asserted claims of US6918801 are no longer enforceable against Weeks Marine or, potentially, any third party. Wilco's ability to assert these specific claims in future infringement actions is effectively eliminated absent a successful appeal overturning the invalidity determination.
Claims dismissed with prejudice; costs awarded to defendantWeeks Marine cleared: no infringement liability on invalidated claims
Weeks Marine prevailed on summary judgment without the need for a full trial on infringement. The invalidity ruling provides a complete defence: if the asserted claims are invalid, infringement liability cannot attach regardless of Weeks Marine's conduct. The defendant now operates with the public record showing those patent claims have been judicially declared invalid, strengthening its position against any renewed assertion of this patent.
Full defence — no infringement liabilityInvalidated marsh vehicle patent opens the competitive landscape
The judicial invalidity of claims 1–5 and 9–15 of US6918801 means competitors in the amphibious and marsh vehicle sector can operate with greater freedom with respect to these specific claims. Companies designing, manufacturing, or operating marsh buggies or similar amphibious equipment in dredging, wetland construction, and marine contracting should monitor whether Wilco holds additional patent assets covering related technology not addressed in this litigation.
FTO implications for amphibious vehicle sectorFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Wilco Marsh Buggies and Draglines, Inc. | Company | /Search in Eureka ↗ |
| Defendant | Weeks Marine | Individual | /Search in Eureka ↗ |
| Plaintiff counsel | Adam Vincent Vickers | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff counsel | George W. Healy , IV | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Gregory D. Latham | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Ian Charles Barras | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Stephen M. Kepper | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Thomas St. Paul Keaty , II | Attorney | Counsel for Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Healy & Jordan PLLC | Law Firm | Representing Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Intellectual Property Consulting LLC | Law Firm | Representing Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Keaty Law Firm LLC | Law Firm | Representing Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Sughrue Mion PLLC | Law Firm | Representing Wilco Marsh Buggies and Draglines, Inc.Search in Eureka ↗ |
| Defendant counsel | Andrew Scott Harris | Attorney | Counsel for Weeks MarineSearch in Eureka ↗ |
| Defendant counsel | Henry Steven Rauschenberger | Attorney | Counsel for Weeks MarineSearch in Eureka ↗ |
| Defendant counsel | Jeffrey Jay Phillips | Attorney | Counsel for Weeks MarineSearch in Eureka ↗ |
| Defendant counsel | Michael K. Leachman | Attorney | Counsel for Weeks MarineSearch in Eureka ↗ |
| Defendant counsel | Robert Lawrence Waddell | Attorney | Counsel for Weeks MarineSearch in Eureka ↗ |
| Defendant law firm | Jones Walker (Jackson) | Law Firm | Representing Weeks MarineSearch in Eureka ↗ |
| Defendant law firm | Jones Walker (Lafayette) | Law Firm | Representing Weeks MarineSearch in Eureka ↗ |
| Defendant law firm | Jones Walker LLP | Law Firm | Representing Weeks MarineSearch in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Louisiana Eastern District CourtSearch in Eureka ↗ |
R&D signals in the amphibious and marsh vehicle technology space
Forward-looking patent and innovation intelligence on amphibious vehicle technology, wetland construction equipment, and the IP strategies of Wilco Marsh Buggies and Weeks Marine.
Wilco's patent portfolio beyond US6918801
With claims 1–5 and 9–15 of US6918801 now invalidated, understanding what remaining IP Wilco Marsh Buggies holds in the amphibious vehicle space is critical for competitors and customers alike. Monitoring Wilco's continuation filings, divisional applications, and any new prosecution activity reveals whether the company is rebuilding its patent position in this niche.
Plaintiff IP portfolio watchFiling trends in amphibious and marsh vehicle engineering
The amphibious vehicle sector — spanning marsh buggies, hybrid land-water platforms, and dredging equipment — is an active area for patent filings in wetland construction and environmental remediation. Tracking recent filings in this technology domain reveals which players are staking out new IP positions and where white space exists for product differentiation.
Sector filing trendsWeeks Marine's IP position in marine construction
As a large marine contractor, Weeks Marine's own patent activity and IP strategy in dredging, marine construction, and amphibious operations may provide signals about where the company is investing in proprietary technology — and where it sees competitive differentiation beyond relying on invalidity defences against third-party patents.
Defendant innovation profileAdjacent innovation gaps in wetland and shallow-water vehicles
The invalidity of US6918801's core claims opens questions about which aspects of marsh buggy and amphibious vehicle design remain patentable and commercially differentiated. Adjacent areas — including drive system innovations, hull materials, environmental compliance features, and autonomous operation for wetland environments — may represent under-patented white space for R&D investment.
White space in amphibious R&DSimilar patent invalidity cases in amphibious and marine construction equipment
Browse related § 102 invalidity disputes and summary judgment outcomes in amphibious vehicle and marine construction equipment patent cases before the Eastern District of Louisiana and comparable courts.
What this case signals for the amphibious vehicle IP landscape
A novelty-based invalidity ruling in this niche domain has direct consequences for how IP risk is assessed across marine construction and marsh equipment markets.
§ 102 invalidity at summary judgment is a high-value defensive outcome
Winning invalidity on novelty grounds at summary judgment — without trial — is an unusually efficient and conclusive result for a defendant. It signals that Weeks Marine's counsel identified strong prior art early and pressed it aggressively through a reconsideration motion. Defendants in similar niche equipment cases should prioritise prior art searching at the outset.
Cost orders reinforce the risk calculus for patent plaintiffs in this court
The court's order that Wilco bear all litigation costs adds financial weight to the defendant's victory. While the Eastern District of Louisiana did not award attorney fees under 35 U.S.C. § 285 based on the available record, a full cost award is a meaningful deterrent signal for patent holders considering assertion in this jurisdiction.
Wilco v Weeks — key questions answered
The Eastern District of Louisiana granted summary judgment in favour of defendant Weeks Marine. The court declared claims 1–5 and 9–15 of U.S. Patent No. 6,918,801 invalid for lack of novelty under 35 U.S.C. § 102, dismissed all of Wilco's claims with prejudice, and ordered Wilco to pay all costs of the matter.
The court found that claims 1–5 and 9–15 of US6918801 each lack novelty under 35 U.S.C. § 102, meaning they were anticipated by prior art. This determination was made on summary judgment following Weeks Marine's motion for reconsideration. The specific prior art references underpinning the § 102 finding are not reproduced in the available public record.
No. The court's final judgment addresses claims 1–5 and 9–15 of US6918801. Claims 6–8 are not referenced in the judgment as recorded in the available public record. Whether claims 6–8 were separately adjudicated, abandoned, or remain in force is not disclosed in the available record.
The court ordered Wilco Marsh Buggies & Draglines to pay all costs of the litigation. This is a standard cost-shifting order upon final judgment and is distinct from an attorney-fee award under 35 U.S.C. § 285. Whether Weeks Marine sought or was awarded attorney fees under the exceptional case standard is not indicated in the available record.
The judicial invalidity of claims 1–5 and 9–15 of US6918801 removes those specific claims as an infringement risk for competitors. However, claims 6–8 were not addressed in the judgment, and Wilco may hold related patent assets not asserted in this case. Companies in the amphibious and marsh vehicle sector should conduct a full FTO analysis against Wilco's broader portfolio before concluding that all risk is eliminated.
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