In the mid to late 1980’s Mercury Marine, a Brunswick Corporation, and Outboard Marine Corporation (OMC) were facing a large number of boat propeller guard product liability / product defect lawsuits. Several of those lawsuits related to kill switches not being installed.

This post is the second of a series of five posts announcing the materials we prepared on 3 studies performed by the boating industry. These 3 studies are currently used as their legal defense against boat propeller guard product liability / product defect cases.

This post is a brief introduction to a large four volume pdf report titled Mercury Marine & Outboard Marine Corp. Propeller Guard Case Legal Defense that can be found at Boat Propeller Guard Product Liability Defense.

Volume I: The Introduction post

USCG Purcell & Lincoln Boat Propeller Guard Study

The U.S. Coast Guard published their own, in house, propeller guard study by Edward S. Purcell and Walter B. Lincoln in 1987.

The study was conducted by reviewing the existing literature on boat propeller guards.

Purcell and Lincoln’s study was viewed as inconclusive by the Coast Guard in part because Purcell and Lincoln reported:

1. They needed accurate propeller strike data
2. Biomechanical testing would need to be performed
3. Mechanical studies would need to be conducted
4. Test for severity would need to be conducted
5. Potential solutions would need to be ranked
6. Acceptable solutions would need to be identified
7. Validation testing would need to be performed

The Efficacy / Effectiveness of Boat Propeller Guards

From 1988 thru 1990 Mercury Marine and Outboard Marine Corporation (OMC), were involved in three propeller guard studies.

Once completed those studies were quickly used in court to defend the boating industry’s position against the use of boat propeller guards / prop guards.

Individuals involved in those studies were used as expert witnesses. They explained the results / recommendations of the studies and how they were derived.

Each of the three studies: the 1989 NBSAC study, the SUNY underwater head impact study, and the SUNY underwater leg impact study are briefly critiqued below.

The U.S. Coast Guard 1989 National Boating Safety Advisory Council Propeller Guard Subcommittee Report

In 1988 U.S. Coast Guard National Boating Safety Advisory Council (NBSAC) formed a subcommittee to study boat propeller guards.

Mercury Marine and Outboard Marine Corporation (OMC) both had representatives on this subcommittee. It was composed of 4 to 7 members of the 21 members of NBSAC. Mercury was represented by their corporate lawyer, Roy Montgomery.

NBSAC’s subcommittee report noted, “Several lawsuits involving tens of millions of dollars have been brought to court in the past two years and have heightened interest in this subject substantially.”

The NBSAC study consisted of a review of the existing literature plus presentations by interested parties.

The study said blunt trauma from impacting a propeller guard at speed was worse than impacting an open propeller. (no proof was provided, see discussion in head impact study section below)

Pages 4 and 5 of the NBSAC study lists three legal theories advanced by propeller guard advocates. Pages 5 and 6 along with pages 20 through 22 rebut the use of propeller guards.

Findings of the 1989 NBSAC Report

The NBSAC report states, “Presentations illustrated that approximately 80 percent of all accidents occur when a boat is operating at speeds in excess of 10 miles per hour.” This is one of several examples of the subcommittee taking statements made by the industry as being factual. (see pie chart on our Chart #9 which shows this statement is not be true). A variant of this comment is repeated on page 17 as, “It was repeatedly stated that a skull impact of 10 mph or more in the water would generally be fatal.” Just because a statement was presented or repeatedly stated by the industry, does not make it true.

In November 1989, NBSAC’s propeller guard subcommittee released its final report. The first recommendation was, “The U.S. Coast Guard should take no regulatory action to require propeller guards.”

This finding was in sharp contrast to USCG’s own 1987 Purcell and Lincoln study. Purcell and Lincoln found much more information needed to be gathered before such a decision could be reached.

Contributions of Dick Snyder of Mercury Marine to the NBSAC Report

Richard Snyder of Mercury Marine was not a member of the NBSAC subcommittee on propeller guards. However, several of his statements made it into the final report. Mr. Snyder was known for repeating certain statements about propeller guards over and over to the media and the industry. We refer to those statements as “Snyderisms”. One of Mr. Snyder’s statements making the final report was, “Due to its revolutions, a propeller generally produces a series of evenly spaced cuts which are relatively easier to repair surgically.” Mr. Snyder’s comment ignores several factors including bleeding to death, water born wound infection issues, amputations, the cost and challenges of prosthetics, and many surgeries being required to repair these injuries.

Another problems with the 1989 NBSAC study, was Mercury Marine knowingly supplied the propeller guard subcommittee with incorrect propeller strike data. This made the problem look much less severe than it actually was. Our report proves this repeatedly using the industry’s own documents.

The Coast Guard records accidents as a series of three events. Mr. Snyder of Mercury only reported First Event data, also known as Primary Event data. First Event data only represents a fraction of the total number of fatalities recorded in the annual U.S. Coast Guard Boating Accident Report Database (BARD).

Then Mr. Snyder subtracted 1/3 of the Primary Event accidents saying they were primarily struck by a boat vs by the propeller. Two previous USCG studies were unable to identify a single accident in which the boat was responsible for the most severe injury.

Next Mr. Snyder subtracted those accidents in which someone was struck by a propeller and drowned. Some of those individuals likely bled out and then drowned or were unable to swim due to the propeller strike.

Snyder Contributions Continued

Mr. Snyder also failed to follow the admonition of Purcell and Lincoln. They called for including propeller injury accident data along with the fatality data. Purcell and Lincoln said that in many instances, the only difference in a propeller injury accident and a propeller fatality is chance. Therefore injury accidents must be included in the analysis of propeller accidents.

USCG Definition of Primary Accident Type

The 1989 NBSAC study also focused on the increased forward facing cross sectional area of the propeller guard vs. the open propeller. When combined with their statements of propeller guard strikes being worse than open propeller strikes, this increase in cross sectional area, portrayed propeller guards / prop guards as being even worse. The claim is humorous today in view of the boating industry featuring countless boats with 3,4, or even more very large outboard motors on them. Multiple large outboards have many times more cross sectional area than added by a propeller guard on a boat powered by a single outboard motor available in 1989.

The 1989 report even says a propeller guard increases the cross sectional area of an open propeller by 3 times (300 percent). That is an example of the exaggerated claims made by the 1989 NBSAC report.

The 1990 Underwater Head Impact Study

A very large donut shaped water tank the State University of New York (SUNY) at Buffalo with a long rotating arm was used for the research project. Michael Scott was hired by Mercury and OMC’s legal departments as the lead researcher of the project. The project was to simulate propeller guard underwater impacts with a human head by using a crash dummy.

Mr. Scott admitted the NBSAC report’s reliance upon blunt trauma to reject the use of boat propeller guards was not supported by experimental data.

Scott’s research was to gather data to support the NBSAC study.

The SUNY head impact study had a lengthy list of problems. Among the most widely known problems being the spring in the crash dummy’s neck was several times stiffer than a human neck in compression. As the propeller guard traversed the dummy’s head it pushed the neck down. This resulted in much high stresses being recorded in the dummy’s neck than would be present in a human neck.

Scott mentioned the neck stiffness problem in early versions of the report. However all mention of neck stiffness issues was missing from the final version of the report.

The outboard motor was placed at zero trim (vertical leading edge) which makes it more difficult for a head to slid down the leading edge of the drive.

The outboard was also configured in a way that made the hydraulic system “stiffer” and eliminated some give in the system that could have reduced peak loads.

The head impact study even cites Event 1 statistics, years after the industry was aware this was improper.

The 1990 Underwater Leg Impact Study

Tyler Kress was hired by Mercury and OMC’s legal department as the lead researcher for the leg impact study at SUNY.

This study was conducted in the tank at SUNY in conjunction with the head impact study.

The leg impact study had a lengthy list of problems as well. One of of the most widely known problems was the use of legs from cadavers that were over 70 years old that had been embalmed for several years.

In addition the legs were impacted perpendicular to the path of the outboard motor (laid horizontally across its path). Most propeller strike leg injuries occur with the person longitudinally coming at the propeller. Such as a swimmer approaching or retreating from the propeller, or legs being in a vertical position near the propeller at the swim ladder.

The outboard motor was placed at zero trim (vertical leading edge). This makes it more difficult for legs to slid down the leading edge of the drive.

The outboard was also configured in a way that made the hydraulic system “stiffer”. This eliminated some give in the system that could have reduced peak loads.

The leg impact study even cites Event 1 statistics, years after the industry was aware this was improper.

The 1990’s

As mentioned earlier the industry quickly began to use these studies and the researchers in boat propeller guard cases. The studies and experts were extremely successful in court. They were also successful in scaring off potential litigants before they even filed legal cases.

In the early 1990’s Mercury and OMC also began perfecting their “get out of jail free card” to put an end to all these propeller cases. They claimed the U.S. Coast Guard’s failure to require all boats to have propeller guards in the 1971 Boating Safety Act established a Federal Preemption. This Federal Preemption prevented requiring propeller guards on any specific boat.

As Mercury and OMC continued to win cases based on Federal Preemption, and the precedent was set. The importance of the three propeller guard studies began to wane. Mercury and OMC basically began to just show up in court, claim Federal Preemption, win the case, and go home.

Federal Preemption was their “get out of jail free card” until the U.S. Supreme Court struck down the Federal Preemption defense in the Sprietsma vs. Mercury Marine case in December 2002.

Since then, the original three studies (the NBSAC study, the SUNY head impact study, and the SUNY leg impact study) have been regaining importance. The 1989 NBSAC report is once again the keystone of the industry’s defense. It is frequently backed up with litigation testing (industry testing of proposed alternatives in a manner to make sure they fail).

The three propeller guard reports are also touted when propeller safety regulations have are proposed by the Coast Guard. This can be seen in the 1995 Federal Register where they are used against a 1995 houseboat and displacement boats propeller safety proposal.