Boat Building Industry Patents & Trademarks Folder

Recreational Boat Building Industry

Patents & Trademarks Folder

Polson Enterprises Research Services

New and Recent Boating Industry Patents

Note: Patents can be viewed by patent number from the:
US Patent and Trademark site. A tiff viewer is required to view the graphics.
Details for downloading one are available there.

Also please note, several additional drive patents are referenced in our drive design rough notes page and in the reference section of our Propeller Driven, Recreational Marine Drive Designs; Learning from the Past with an Eye to the Future paper.

The U.S. Patent Applications referenced below can be viewed by number from the:
US Patent Application Search page. Delete the slash used to separate the year from the application number when using the Application search system.

U.S. Patent 7,794,295
Marine Drive
Michael Beachy Head

Follow up patent to U.S. Patent 6,186,845 and 7,588,473, 
a transom mounted drive that rotates in the plane of the transom to steer.
Now known as the Caudwell Marine Axis Drive.
The patent does a nice job of citing many stern drive patents, but does
not discuss many of them in detail.

U.S. Patent 6,478,646 Drive device of inboard and outboard drives 12 Nov. 2002 Teruhito Fuknoka, Yuji Hashimoto, Kazuyoshi Shinada Assigned to Yanmar Diesel Through hull drive where something similar to a non-trimmable sterndrive mounts on engine bell housing then goes straight down through the hull.
U.S. Patent 6,468,119 Composite stern drive assembly 2 Oct. 2002 Emil Hasl, Matt Wilkins, Chris Savole, Jeff Hardesty, Mark Skrzypek, and Richard Holmberg. Assigned to Volvo Penta Extensive patent (25 pages and 49 claims) on Volvo's new composite stern drive.
U.S. Patent 6,469,641 Marine vessel monitoring system and method Oct. 22, 2002 David and Anthony Lash Assigned to Beacon Marine Monitoring system provides remote access to security and statistical information on unattended boats.
U.S. Patent 6,458,003 Dynamic trim of a marine propulsion system Oct. 1, 2002 William Krueger Assigned to Bombardier Bombardier's version of an autotrim system using some technologies that were available years ago. Interestingly, it allows operators to select what they wish to optimize: speed, fuel efficiency, etc.
U.S. Patent 6,450,845 Passive occupant sensing system for a watercraft Sept. 17, 2002 Richard Snyder and Richard Staerzl Assigned to Brunswick Boating application of auto child seat detection technologies. Since it does not need to detect weight (only presence of driver) an infrared system is used to create a tetherless occupant detector (dead man switch).
U.S. Patent Application 2002/0127928 Propulsion system for motor boat Sept. 12, 2002 Fabio Buzzi Engine actually rides and pivots atop the propeller. Engine points forward and a V-Drive changes direction ot the prop back down under the engine. Mr. Buzzi is a well known European marine designer.
U.S. Patent 6,435,923 August 20, 2002 Two speed transmission with reverse for a watercraft Arthur R. Ferguson Assigned to Bombardier Two stroke transmission with reverse mounts in the gimbal housing area of a stern drive.
U.S. Patent 6,439,937 August 27, 2002 Boat propeller transmission Staffan Mansson and Oddbjorn Hallenstvedt Assigned to Volvo Penta Two speed planetary transmission mounts "in-the-leg" of a stern drive.
U.S. Patent 6,431,927 August 13, 2002 Outboard propeller drive system for watercraft Michael Sage Transom mounted drive with independently adjustable depth of operation and attitude (trim is independent of prop depth) for high speed craft.
U.S. Patent 6,425,788 July 30, 2002 Controllable pitch propeller Jan-Erick Lindholm Assigned to AB R&D Marine OY of Finland Hydraulically shifted propeller for outboards and stern drives.
U.S. Patent 6,406,344 June 18, 2002 Marine exhaust with dual cooling Gerald Bland, James Bellantonio, Gerald Neisen Assigned to Bombardier Stern drive engine pulls water from a through hull pickup and a skeg mounted pickup. May be remains of a patent filed earlier by OMC.

In recent months Brunswick has recieved several patents for control systems. It is very apparent considerable effort was and may still be devoted to applications of this nature.

     U.S. Patent 6,200,177
     March 13, 2002
     Mulit-speed marine propulsion system with improved automatic
     shifting startegy based soley on engine speed.
     Phillip Scott and  William Stephenson
     Two speed transmission is shifted based on engine speed AND
     rate of change of engine speed.

     U.S. Patent 6,273,771
     August 14, 2001
     Control system for a marine vessel
     George Buckley, Vojislav Divijakovic, Phillip Gaynor, Jeffrey Ehlers,
     and Daniel Clarkson
     Many input and output devices on a boat communicate with one 
     another. Patent contains an excellent review of prior devices
     in  this area.

     U.S. Patent 6,377,515
     April 23, 2002
     Synchronized Sonar
     Robert Healy (Zebco)
     Sonars are synchronized to allow them to be used near each other
     and not interfere with each other.

     U.S. Patent 6,378,506
     April 30, 2002
     Control system for an engine supercharging system
     Suhre Blake and Jeffery Ehlers
     A bypass control valve is controlled by engine control module
     as a function of manifold absolute pressure and temperature within
     an intake in conjunction with barometric pressure.

     U.S. Patent 6,379,114
     April 30, 2002
     Method for selecting the pitch of a controllable pitch
     marine propeller
     Carl Schott, Blake Suhre and Matthew Manthey       
     Control agorithm selects pitch as a function of difference of desired
     engine speed and actual speed and actual current pitch of propeller.
     This patent provides control diagrams, test data and extensive information.

     U.S. Patent 6,382,122
     May 7, 2002
     Method for initializing a marine vessel control system
     Phillip Gaynor, Kurt Willows and John Wyant
     System automatically determines how many marine propulsion
     devices are on the vessel and prompts the builder or user to
     enter various commands to indentify specific devices and components
     and their association with a specific drive.

     U.S. Patent 6,390,862
     May 21, 2002
     Pump jet steering: method during deceleration
     Charles Eichinger
     Engine control system slows the engine deceleration according to a 
     preselected protocol or profile to allow more water to pass through
     the jet pump so low speed steering during deceleration is improved.

     U.S. Patent 6,393,347
     May 21, 2002
     Data recording method for a marine propulsion device
     Richard Snyder, Robert Haddad and Steven Basso
     System uses three data logs covering different time increments
     (a short time, intermediate time and a long time). These are 
     essentially airplane black boxes that can be used to determine
     reason for failure. They state use of them for determining what 
     caused a failure. They might also find application in voiding 
     warranties for when the engine has been abused.

     U.S. Patent 6,402,577
     June 11, 2002
     Integrated hydraulic steering system for a marine propulsion unit
     Kerry Treinen and Darin Uppgard
     Steering actuator becomes an integral part of support structure for
     stern drives or outboards. 

     U.S. Patent 6,406,259
     June 18, 2002
     Method for changing the pitch of a controllable pitch propeller 
     during gear shifting operations
     Carl Schott
     Device monitors future or impending gear shift operations, shifts
     prop to low or zero pitch during shifting, then returns to blades to
     the original or current setting to reduce prop hub shock loads during

     In addition to the patents above, their recent infrared propeller
     to protect people in the water near propellers discussed further 
     below and on our 2002 Propeller Guard Update page 
     is intended for use in a control system. (U.S. Patent 6,354,892  March 12, 2002)

Brunswick runs afoul of Genmar internet sales promotion patent application.

U.S. Patent Application 2002/0038237
Published March 28, 2002
Mark Duchow
System requests information from potential customer, identifies 
product in stock at a specific reseller and prints a voucher for
potential customer including a cash value discount and an expiration
date. This method was recently used very sucessfully by Genmar 
(they obtained a license from Mr. Duchow). When Brunswick 
announced a similar program, Genmar challenged them based 
on this patent application.

U.S. Patent 6,368,169
April 9, 2002
Marine engine cooling system with siphon inhibiting device
Matthew Jager (MerCruiser). Assigned to Brunswick
Floating ball prevents water from siphoning backwards soon after
the hot engine is shut off. It also allows draining the system. 

U.S. Patent 6,361,387 March 26, 2002 Marine propulsion apparatus with dual driveshafts extending from a forward end of an engine. Daniel Clarkson (MerCruiser). Assigned to Brunswick. Engine is mounted in rear of boat with output shaft facing the bow. Power is split to two rearward shafts (one running along each side of engine). Each shaft drives one propeller. Unit acts as a set of twin engines and the single engine can be mounted further rearward to improve center of gravity and provide more usable space near the back of the boat. The patent cites and discusses "Smallcraft Propulsion" by Robert W. Hobbs, pubished in Popular Boating Magazine in 1962. The article details 25 different arrangements of marine propulsion.
U.S. Patent # 6,354,892 Safety device for a marine vessel Richard Staerzl assigned to Brunswick March 12, 2002
The patent describes a device (infrared sensor in a tube to limit sensor area) for detecting people near an operating propeller or bow thruster. It sounds alarms, deactivates the propeller or takes other appropriate action when people are in the danger zone. We have indepth coverage on our Propeller Guard Update Page

U.S. Patent Application # 2002/0023579
Filed 28 February 2002
High speed electric watercraft
James Profitt, Joseph Peek, Kayo Motesenbocker, Marvin Motsenbocker
High speed electric motor propelled recreational water craft.
Body of craft rises above water on outriggers (skis).

U.S. Patent Application # 2002/0017277 February 14, 2002 Four-cycle engine for marine drive Isao Kanno Variable valve timing outboard. Might be Sanshin's (Yamaha's) answer to Honda's VTEC.

Showa received three patents on trim devices in late 2001 and early 2002.

U.S. Patent 6,328,616
December 11, 2001
Trim-tilt device for a marine propulsion unit
Tamotsu Nakamura, Omito Toyoshima, Hisao Takayanagi, Keiji Orihara

U.S. Patent 6,332,817
December 25, 2001
Trim-tilt device for marine propulsion unit
Tamotsu Nakamura

U.S. Patent 6,368,168
April 9, 2002
Tilt device for marine propulsion unit
Yasuo Funami

The first two describe an outboard trim system with the cylinder
encased in a reservoir to reduce cylinder rod corrosion. 
The last one describes trim motor housing construction
regarding heating problems.

U.S. Patent 6,350,165 Feb. 26, 2002 Marine stern drive two speed transmission Gerald Neisen Assigned to Bombardier "In the leg" two speed transmission Note: this patent was followed up by U.S. Patent Application 2002/0072279 A1 Published Jun 13, 2002 Marine stern drive two speed transmission Gerald Neisen
U.S. Patent 6,289,853 Sept. 18, 2001 Water Injection System for an internal combustion engine of a marine propulsion system Thomas Walczak and Stephen Riese Assigned to Brunswick Water injection of marine engine using filtered "raw water" RBBI Comment - Water injection is widely used in diesels on large vessels to reduce NOx emissions. It is also used in several high performance recreational marine gasoline engines to help cool the engines (especially supercharged ones) and to increase performance. We suspect this patent may have some validity problems.

Patents prior to September 15, 1998

5,807,151 Sept. 15, 1998       USPTO abstract
Sumino assignor to Sanshin

Counter rotating surfacing propeller blade design for partially surfacing drive.. See also patent 5,800,223 below.

5,803,410 Sept. 8, 1998
Hwang assignor to NASA.

Skin friction reduction by micro-blowing technique. Use of small air bubbles to reduce hull friction.

5,800,223 Sept. 1, 1998
Iriono and Sumino assignors to Sanshin

Marine propulsion device including counter rotating propeller blade design for partially surfacing drive. Patent details a blade design to allow closer placement of the props. See also patent 5,807,151 above.

5,797,371 Aug 25, 1998
Nanaka assignor to Sanshin

Cylinder disabling control system for multi-cylinder engines. Automatic monitoring of engine turns off some cylinders when power requirements are low.

5,791,955 Aug 11, 1998
Davor Rinck. Federal Republic of Germany.

Cover for boat propulsion units. Foam lined case for transportation protection and to reduce theft of items from drive.

5,791,950 11 Aug 1998
Robert B. Weronke, Michael A. Karls, Roger E. Koepsel, Donald F. Harry assignors to Brunswick (Mercury Marine)

Twin propeller marine propulsion unit.

5,766,047 16 June 1998
Charles F. Alexander Jr. and Daniel F. McCormick assignors to Brunswick (Mercury Marine)

Twin propeller marine propulsion unit. Single prop at low speed, dual prop at high speed.

5,755,605 26 May 1998
Michael Asberg assignor to AB Volvo Penta.

Propeller drive unit Z drives thru bottom of hull used to regulate trim.

5,740,750 Apr 21, 1998
Michael Triantafyllou and David S. Barrett assignor to MIT.

Method and apparatus for reducing drag on a body. Wave like motion (this is the MIT Robo Tuna project).

5,727,495 17 March 1998

Surface effect vehicle. Patent has excellent references to other surface effect information.

5,722,866 3 March 1998
Lennart Brandt assignor to A.B. Volvo Penta

Propulsion arrangement for marine vehicle. Jet drive that generates trimming forces.

5,720,636 24 Feb 1998
Donald E. Burg.

Marine propulsor. Jet drive with gas at top of jet during high speed operation. All water at low speed operation.

5,711,742 27 Jan 1998
Brian M. Leinonen, Phillip T. Scott, Robert F. Novotny assignors to Brunswick (MerCruiser).

Multispeed marine propulsion system with automatic shifting mechanism.

5,667,415 16 Sept. 1997
Howard M. Arneson.

Marine outdrive with surface piercing propeller and stabilizing shroud. Fin structure prevents drive from "walking" boat laterally.

5,647,780 July 15, 1997
Yukiharu Hosoi assignor to Yamaha

Vertically Adustable Stern Drive for Watercraft. Tilt, trim, lift mechanism maintains trim while raising and lowering the drive.

5,632,658 May 27, 1997
Benjamin H. Chen and Carol L. Tseng assignors to The United States of America represented by the Secretary of Navy

Tractor podded propulsor for surface ships with a forward mounted propeller resulting in less drag than conventional open shafts and struts.

5,630,704 May 20, 1997
Hubert S. Gilgenbach and Michael P. Mihelich assignors to Mercury Marine (Brunswick)

Propeller drive sleeve with asymmetric shock absorption that provides additional cushion in reverse where the gearing is weaker.

5,628,285 May 13, 1997
Andrew K. Logan, Matthew W. Jaeger, Terry D. Axton, William E. Hughes, David J. Gruenwald, James E. Erickson assignors to Mercruiser (Brunswick)

Drain valve for a marine engine that automatically drains the engine when the temperature drops toward freezing.

5,613,470 March 25, 1997
Shiomi; Kazuyuki
Shigedomi; Hideo
Fujita; Yasushi
Matsuda; Yoshiyuki
Soda; Chiharu
Kiku; Kazuomi
Furuya; Kentaro
assignors to Honda

Outboard Engine Assembly. This patent has had some problems because it was originally filed in April of 1993, then a continuation was filed in November of 1994 and it is only now coming through the system. Must have been something in the filing they wanted and the PTO didn't want to give it to them. It shouldn't take even half of 4 years for a Honda patent to go through unless there are complications.

5,601,464 Feb. 11, 1997
Hiroshi Ogino and Yoshikazu Nakayasu assignors to Sanshin

Tranmission for Counter Rotating Propulsion Device

5,599,218 Feb. 4, 1997
Keith W. Schmidt, Brian R. White, Howard F. Africa assignors to Brunswick (MerCruiser)

Ski Boat Marine Exhaust System Configuration

5,598,700 Feb. 4, 1997
Hezi Varshay and Alon Gany assignors to Dimotech Ltd.

Underwater 2-Phase RamJet Engine

5,597,334 Jan. 28, 1997
Hiroshi Ogina assignor to Sanshin

Outboard Counter rotating Transmission


5,584,734 Dec. 17, 1996
Hiroshi Ogino and Takashi Iwashita assignors to Sanshin

Lower unit for main outboard drive. Special shaping and blending of nose cone with a vertical member make a frontal tear drop shape that remains consistent through the trim range and inhibits water boundary layer separation. Note- this patent has 24 claims.

5,584,225 Dec. 17, 1996
Lennart Arvidsson, Anders Bergquist, Stig Larsson, Lennart Uhlander assignors to Volvo Penta.

Hydraulic cylinder, especially a trim and tip cylinder for outboard type boat propeller drive units.

5,580,289 Dec. 3, 1996
.ANG.sberg, Mikael assigor to Volvo Penta.

Transmission device in an Outboard drive unit for boats

5,579,729 Dec. 3, 1996
Andrew K. Logan, Matthew W. Jaeger, Terry D. Axton, William E. Hughes, David J. Gruenwald assignors to Brunswick

Separating Apparatus for the Cooling System of a Marine Engine

5,575,698 Nov. 19, 1996
Hiroshi Ogino assignor to Sanshin

OB Drive Transmission System Transmission for Counter-rotational propeller systems with increased flow area for exhaust discharge behind the transmission.

5,575,231 Nov. 19, 1996
John P. Metcalf assignor to OMC

"Floatation Lined Pontoon Log" They partially line the pontoon "logs" with foam to help reduce leaks and reduce sound transmissions. We have included a partial text copy of this patent.

5,562,508 Oct. 8, 1996
Christian Rodskier of Sweden and Stig Johansson of Virginia, assignors to AB Volvo Penta

"Marine Propulsion Arrangement" Somewhat of a cross between a transom mounted outboard and a stern drive.

5,558,548 Sept. 24, 1996
Niclas Olofsson, Vase; Anders Rydberg, Arboga, and Oddbjorn Hallenstvedt, Valskog, all of Sweden, assignors to AB Volvo Penta

"Propeller Drive For Boats" This very Interesting patent describes a single surfacing propeller and a method of using a "fin" to prevent the usual "pull to one side" of the surfacing prop.

5,558,038 Sept. 24, 1996
Don B. McNamara assignor to OMC
"Boat Hull Gunwale Construction And Process Therefor" Excellent description of Resin Transfer Molding (RTM) hull process. This patent lays some good groundwork for patents and processes of this type.

5,556,313 Sept. 17, 1996
Hiroshi Ogino assignor to Sanshin

"Outboard Drive Transmission" A fwd-rev transmission for counter-rotating drives

5,545,063 August 13, 1996
Hendrick W. Haynes (an individual inventor)

"Chambered Anti-Coanda Jet Marine Propulsion Device With Gaseous Boundary Layer For A Thrust Jet Flow Stream Exhibiting Staged Controlled Boundary Layer Separation Properties, Vessel Trim Adjustment, And Movable Thrust Vector" . Teaches the use of a gas boundary under the hull of a water jet to reduce friction, control trim, etc.
We actually had a brief chat with Mr. Haynes on 11 November 2008 due to me previously mispelling his name. He is still very active in this field.

5,527,194 18 July 1996
William A. Strong, Gerald E. Wentz, John W. Behara assignors to Mercruiser (Brunswick)

Thrust Sensor For Marine Drives. Sensor for prop thrust of single prop and counter rotating prop drives.

5,518,060 May 21, 1996
Terrance M. Cleary and Thomas E. Bilderback assigned to Brunswick.

Lost Foam Casting Patern Making Method

Brief Introduction to Patents

We encourage you to follow the links in our Patents Segment of the "Other Useful Links" Section and become familiar with the various information available from them. If you are near a Federal Depository Library you can contact them, find out what specific tools their site has, and learn more about the patent system from them. A link to help you find the nearest Federal Depository Library is in the Libraries segment of our Other Useful Links section.

The patent classification system allows searching for similar items. Patents are classified by class subclass. They are also cross referenced to other classes and subclasses they appear to have some relationship to. Three classes of specific interest to the recreational boating industry are Class 114 (Ships), Class 440 (Marine Propulsion) and Class 123 (Internal Combustion Engines). An International Classification System is also used.

If you are an independent inventor thinking about trying to license an idea to a firm in the industry, see our Inventors Page. If you are a firm trying to develop a marine product, as Polson Enterprises we provide assistance in developing new marine technologies.

Patent Legal Battles in the Industry

Sea-Doo, Yamaha and Bombardier

Several years ago, Yamaha filed against Bombardier, claiming watercraft (PWC) features invented and patented in Japan were stolen by them. The battle still rages with Bombardier claiming the features were already in use by Yamaha before they were patented. The situation is detailed in The Boating News

Regal FasTrac Hull Design Controversy

There was a dispute over Regal's FasTrac hull design. A naval architect, Harry Schoell, claims it infringes on his Duo Delta Conic hull patent. We cover this dispute on our Regal FasTrac Hull Design Controversy Page.

Lough v. Mercury Marine

One of the current patent battles that may have just been laid to rest was between an individual (Steven Lough) and Mercury Marine over a brass seal. We have extensive coverage of this case on our Lough v. Mercury Marine Page.

Volvo v. Brunswick (Twin Prop)

One recent patent battle was the fight between the Mercruiser Dual Propeller Bravo-Three and the Volvo Duo-Prop. This was a very interesting case. The general public had the concept that Volvo had patented the dual counter-rotating propeller concept and owned it, but that concept had actually been in limited use for many years. The areas being contested were some propeller blade design parameters. The actual fight was over patent Volvo #4,741,670, or more properly - over its reissue as Re.#34,011 on 28 July 1992. The details of this case are on the Volvo vs. MerCruiser Page

Bonito Boats, Inc. v. Thunder Craft Boats, Inc.

The case of Bonito Boats, Inc. v. Thunder Craft Boats, Inc. 489 U.S. 141 (1989) received a lot of comments in the legal literature. It held that federal patent law preempts Florida statute prohibiting the copying of boat hull designs by using a direct molding process. One of the discussions is in the Iowa Law Review Volume 76 (1991) pages 959-1010. The title of the article is, "Federal Intellectual Property Law and the Economics of Preemption". Basically the Bonito Boat hull was not patented (the court said it provided too slight an advance to be patented) and thus belonged to the public and should be able to be directly copied by the public since it was not patented. The Florida statute had prohibited direct mold copying of any boat hull (as had several other states), the federal court said direct mold copying of non-patented boat hulls by competitors (or anybody else) was legal.

Interesting or Historically Significant Patents

Some interesting patents or patents of historical significance are listed below. We are not providing copies of them on this site. The numbers will help you find the abstracts or full copies through the normal patent information sources.

One of the most historic and colorful patents in the industry is the original stern drive patent by James Wynne (patent # 3,376,842) filed May 11, 1960 and issued April 9, 1968. We have a page devoted to the Invention of the Stern Drive that discusses the colorful beginning of this revolutionary drive.

Some interesting very old patents:

Some drive patents:
Some of the Blackhawk Surface Drive Patents are
Some steering system patents are:

Here are several of the trim cylinder patents in the industry:
Some propeller guard type patents:

There are a number of patents on Low Styrene Emission Resins (Boat Hull Application)
Some other interesting patents:

Harley Sound Trademark

Trademarks and Copyrights have not been playing a major part in the industry to date. One recent Trademark situation was Harley's filing for a trademark on the distinctive sound of their motorcycles.

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