RFID Boat Kill Switches (Engine Cut-Off Switches) – Five PGIC Invention Disclosures Posted August 29, 2011

Today, August 29, 2011, we, the Propeller Guard Information Center, posted five RFID (Radio Frequency Identification) invention disclosures. While they have other implications as well, they were primarily inspired by problems surrounding boat engine kill switches (emergency engine cut-off switches).

We (Polson Enterprises and the Propeller Guard Information Center) initially retained all rights to these inventions (including their use in non-boating applications). However, one year later (29 August, 2012) all five inventions were placed in the public domain.

Existing lanyard boat engine kill switches (emergency engine cut-off switches) are used to kill the engine if the operator falls overboard. Boats often begin spinning wildly in the “Circle of Death” after the operator has been ejected. A boat operator that falls overboard while the boat is underway may be struck repeatedly by the boat and/or propeller as the boat circles.

Lanyard boat kill switches are rarely used by boat operators due to the hassles of hooking them up. Sensor based kill switch systems such as Autotether and MariTech’s Virtual Lifeline and CAST have began to address some of the hassles involved with using lanyards. Our RFID tag based invention disclosures illustrate a different sensor based approach with some additional advantages.

Our five invention disclosures are:

1. Implantable Non-Unique RFID Tag / RFID Chip / RF Reflector Used to Detect Human Presence and/or Human Proximity and/or Human Location invention.

2. Non-Unique RFID Fob / RF Reflector Used to Detect Human Presence and/or Human Proximity and/or Human Location invention.

3. RFID Clothing Used to Detect Human Presence in Boat Kill Switch Applications invention.

4. RFID Life Jacket / PFD Used to Detect Human Presence in Boat Kill Switch Applications invention.

5. Boat Engine Kill Switch System for Integrating With RFID Tags or RF Reflectors invention.

For those who may find the disclosures a bit complex, they basically describe boat kill switch systems that could supplement the existing lanyard system with a sensor based system utilizing an RFID (Radio Frequency Identification) tag. That RFID tag could be an integral part of a life jacket, an integral part of clothing worn by the boat operator, a key chain type fob, or actually implanted into the boat operator. If the operator strays too far from the helm, the system kills the engine. This series of invention disclosures describes the various methods (implant, fob, clothing, life jacket) and the system itself.

We suspect the life jacket and clothing methods hold the most promise.

We recognize that even though the inventions described are based on long established technologies, these particular combinations are still at the earliest technology readiness levels, especially in the recreational boat environment. Plenty of foreseen and unforeseen hurdles lie ahead in any efforts to commercialize them. We posted them at this stage in their development to help stimulate progress in this area.

Many of the propeller safety devices on the market today were inspired by media reports of local propeller accidents. We hope exposure of propeller safety technology developments can also inspire more people to bring their ideas to bear on these problems.

We welcome comments and suggestions related to these five RFID invention disclosures. We asked viewers of the individual disclosures to leave any public comments they may have on this post.


  1. RFID have been around for some time and have been used in the claims mentioned in Automobiles for years.
    So what is not obvious and unique about the claims proposed? In your use of term embedded which seems to be the theme to your claims, all RFID’s are embedded again what is unique about your claim.
    All of the proposed claims would be obvious within the current use application for RFID’s.

  2. We posted a series of inventions disclosures leading up to RFID life jacket kill switch boat invention. I wrote a lot of claims on the inventions leading up to the RFID life jacket kill switch system, including several having application outside the boating industry. I suspect some of those claims may have some prior art issues and alluded to that in our prefix to them, “We (Polson Enterprises, owner of the Propeller Guard Information Center) claim the the inventions described in this invention disclosure not previously legally claimed or patented by others and now make a public disclosure of them.”

    As you mentioned, I suspect some of that prior art comes from the automotive industry. We were just making a public disclosure of an invention and trying to retain and much rights to that invention as possible. Therefore, I basically wrote some broad claims and stated whatever in there is not claimed by others is ours. The claims are obviously not legally prosecuted patent claims. They just serve to more precisely define the invention, its potential uses, and how it works.

    I also recognize that we will loose those rights (the ones not belonging to others) if we have not filed for them before the various patent clocks run out.

    In my opinion, RFID clothing or RFID life jackets as part of a boat kill switch system as described by us are unique and not obvious. But, everybody is entitled to an opinion, and I appreciate you sharing yours.

    The term “embedded” was used a few times to refer to the RFID tag being contained within something vs. just being stuck onto it, or attached to it by a keychain, etc.

    Thanks for you comments.


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