Polson Enterprises Research Services

Reference Materials

Polson Enterprises Research Services

If you are interested in additional references in specific areas, please contact Polson Enterprises.


Parra's Marine Biological Sensing Research

Jorge Parra did extensive work in the area of detecting biological signals in water. Perhaps his work on detecting presence by detecting biological signals (cardiological, skeletal and respiratory noises) could be utilized to detect people near propellers. U.S. Patent 5,146,208 does an excellent job of presenting his research in this area. His patents (not all of which are still active) include:

Other Biological Sensing Efforts

Ambient Noise Imaging

Faucet Sensors


Aquatic Wildlife Detection Sensors

Fish Farm Security Systems

The patents below can be found in the Worldwide Patents section of the European Patent Office

Other Military Sensors

Miscellaneous Sensors

New Sensors Encountered After this Paper was Published

Signal Conditioning in Noisy Environments


Conventional Propeller Guards

See the recent US Coast Guard study,
"Propeller Injury Protection, an Evaluation of Commercially Available Protection Devices" A recent patent of note is: 5,759,075 Propeller Guard
assigned to PropGuard. I visited with them at IMTEC98 and found them very devoted to improving water safety. They also showed me a prototype of a small pager sized device that could be worn by swimmers to allow them to be detected near the propeller. Their product brochure included prop strike statistics and a medical study of those injured.

Interesting Propeller Devices

These units do not fit the conventional propeller guard category, but have some implications in that area.

Propeller Injuries

Propeller Injury Lawsuits

Typical cases involving propeller injuries include:

In Ryan v. Brunswick the Michigan Supreme Court affirmed: 209 Mich App 519; 531 NW2d 793 (1995).
Another version of the case report is online in Lawyer's Weekly.

The recent Lewis v. Brunswick suit involved an Oklahoma teenage girl who fell into the water and was fatally injured by a propeller. The decision in favor of Brunswick was upheld in the 11 Circuit and the family pushed the case to the Supreme Court. The case was settled for an estimated $700K (probably small in terms of the legal expenses) but sets a new precedent for Brunswick which has not backed down from a prop suit. Perhaps they felt the court was about to reverse their longstanding defense? This case should particularly interest boat builders in new methods of protecting people in the water.

Several legal consultants specialize in this area, one of them, Mr. Tom Ebro maintains a web site called Aquarisk. On that site he maintains a list of prop cases I am reproducing below. His brief descriptions provide some insight into the types of situations propellers injure people.

8504 Plaintiff Coral Gables, Florida Rendall v. Karabas Foot severed by boat's propellers
8511 Defense Metairie, Louisiana Undetermined Occupants were ejected and struck by boat
8716 Plaintiff Baton Rouge, Louisiana Evans v. Bennett Occupant fell overboard and was run over
8802 Plaintiff Philadelphia, Pennsylvania Levin v. Bates Inattentive boat driver ran over a fallen skier
8834 Plaintiff Key West, Florida Calabro v. Burgess Raceboat collided during race; prop injury
8908 Plaintiff Bradenton, Florida Cole v. Eubanks & Manatee County Boat ran over a skindiver; leg was amputated
8923 Plaintiff Miami, Florida Redmon v. Carr Boarding waterskier sliced his leg on prop
8945 Plaintiff New York, New York Schenck v. Walt Disney World Ferryboat ran over a patron in rental boat
8954 Plaintiff Bloomfield, Michigan Koble v. Tabor Swimmer was run over by a boat *Fatal
9037 Plaintiff Clearwater, Florida Meyer v. City of Clearwater Boat ran over a swimmer close to buoys
9120 Defense Miami, Florida Stamper v. Goldring/Hewes Boat without kill-switch ran over the driver
9259 Defense Costa Mesa, California Riley v. Zodiac of North America Boat ran over ejected driver, prop injuries
9330 Plaintiff Glasgow, Kentucky Raines v. Renken Boat Manufacturing Boat without kill-switch struck ejected driver
9350 Defense Ventura, California Kavezadeh v. Zodiac of France Prop injury, woman fell overboard off pontoon
9401 Plaintiff Kissimmee, Florida Caban v. Walt Disney World Prop injury, boy's arm mangled by propguard
9469 Plaintiff Dallas, Texas Ramsey v. Catfish Bay Marina Boat rental propeller laceration on fallen tuber
9538 Plaintiff Seattle, Washington Karl Becker v. US Marine Boat's sharp turn threw passenger, cut by propeller
9574 Plaintiff Salisburg, Maryland Higgins v. Ocean City Amusement Park Small skeeter boat flipped, passing propeller cut rider

Aircraft Propellers

Airplane propellers provide a pretty direct airborne analogy to marine propellers.

Rescue Operations

Devices to Locate People for Water Rescue

Other Rescue Situation Body Detectors

Swimming Pool Monitors

Propeller Guard Articles

Coast Guard & Industry Meetings

Some Suggested System Design Parameters

Patent Classes and Search Words

International Patent Class B63H 005/16 and U.S Patent Class 440/72 cover traditional propeller guards. US Patent Classes 340/565 and 340/573 contains many of the sensors of interest. International Patent Class G08B 013/00 also contains some related sensors.

Some search words we found especially useful in the various databases and search engines while researching this topic were:

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