The SM-3 lifebuoy self-igniting marker light  is a high intensity LED strobe which provides 360° visibility for approximately 2 miles. This compact yet durable marker light facilitates rescue by automatically activating and beginning to strobe when in the water, working for over 40 hours at 30oC (86oF) or over 24 hours at -1oC (30oF). Perfect for commercial marine, petro-marine, cruisers, and any other application needing a reliable Crew Overboard Marker (COB) light, the SM-3 floats upright in all conditions, ensuring it will keep shining when you need it the most.


With a minimum light intensity of 3 candelas throughout its entire operating life, this high intensity LED strobe marks a crew-overboard site with each brilliant flash. It automatically rights itself and activates when in the water, ensuring that activation is never an issue that a crew member in distress needs to worry about. The SM-3 operates on 2 AA Lithium batteries and the batteries are user-replaceable, allowing the potential for a longer product life than the many disposable lifebuoy lights on the market.

The supplied mounting bracket holds the SM-3 secure in the roughest of conditions but it is still readily accessible when needed in an emergency. Additionally, while the SM-3 and its bracket are significantly smaller than the SM-2 counterparts, the SM-3 bracket conveniently maintains the same mounting hole pattern as the SM-2, allowing for easy retrofit with no additional adapter plate required.

The SM-3 is USCG/MED/SOLAS approved for use around the world and this durable LED marker light, therefore, provides an excellent option for vessels needing to meet USCG and SOLAS carriage requirements for lifebuoy self-igniting lights. As per USCG and SOLAS requirements for passenger and cargo vessels, at least one-half of the total number of lifebuoys on the vessel must be fitted with a self-igniting light. Minimum carriage requirements are based on the length of the vessel and can range from a minimum of four to a minimum of fifteen lifebuoys with self-igniting lights per vessel.

Rugged design leads to the greater flexibility of use. While the SOLAS standard only calls for a 30-meter drop test, the SM-3 has been drop tested to 76 meters. This makes the SM-3 a versatile option for use on a variety of platforms or vessels of different sizes.

With its easily replaceable Lithium AA battery power source, the SM-3 will give years of service and be ready when called upon.


Features and Benefits :

  • Bright light in all directions (360° visibility)
  • UV resistant polycarbonate case
  • Lightweight and compact in size
  • Easy bracket installation
  • The bracket is included and maintains same hole pattern as SM-2 for easy retrofit
  • Automatically rights itself and activates when in the water
  • High intensity LED strobe
  • Floats upright in all conditions
  • Minimum 40 hours continuous operating life at 30oC (86oF) or over 24 hours at -1oC (30oF)
  • User-Replaceable AA Energizer L91 Lithium Batteries (Not Included)

Lifebuoy Self-Igniting Marker Light  Warranty


This product is warranted against factory defect in material and workmanship for a period of 1 (one)* year from date of purchase or receipt as a gift. During the warranty period ACR Electronics, Inc. will repair or at its option, replace at no cost to you for labor, materials or return transportation.

This warranty does not apply if the product has been damaged by accident or misuse or as a result of service or modification by other than the manufacturer. The COMPANY MAKES NO REPRESENTATION OR WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, AS TO MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR ANY OTHER MATTER concerning THIS PRODUCT, except as otherwise expressly stated in the previous paragraph. The Company shall not be liable for consequential or special damages. To place the warranty in effect, choose a form above and complete it entirely. Or you may fill out the registration card accompanying your product (if applicable) which must be returned to ACR Electronics, Inc. within ten days of purchase.

*Five Years for the following products: EPIRBs, and PLBs.

Lifebuoy Self-Igniting Marker Light Specification

Name SM-3 Lifebuoy Self-Igniting Marker Light
Product Description Strobing Crew-Overboard Marker Light
Model Number SM-3
Application Commercial maritime applications including petro-marine, workboats, cruise liners, tugs and workboats, supply vessels, cargo vessels, passenger vessels, fishing charters, etc.
Size 9.9” (253 mm) Length
2.2” (56 mm) Diameter
Weights 0.66 lbs (300 g) Light Only
0.71 lbs (330 g) Light with Batteries
0.90 lbs (406 g) Light with Batteries & Bracket
Batteries 2 AA Lithium Batteries (L91) / User Replaceable (Not Included)
Material UV Resistant Polycarbonate
Color International Safety Orange
Activation Automatic gravity switch
Operation Throw SM-3 overboard or turn upright and the strobe light will automatically begin to flash
Light Intensity Minimum of 3 candelas per flash in all directions of the upper hemisphere
Visibility 360o visibility
Flash Rate 50–70 times per minute
Buoyant Yes
Lamp Ultra-Bright LED
Operational Life 40 hours over 3 cd at 30oC (86oF)
24 hours over 3 cd at -1oC (30oF)
Drop Test Drop tested to 76 meters (USCG/SOLAS/MED only call for 30 meters)
Warranty 1 year
Approvals USCG / MED / SOLAS (Click Downloads for a complete list)
Mounting Bracket UV resistant polycarbonate bracket included / Same mounting hole pattern as previous SM-2 Model for easy retrofit



Q: Is the SM-3 a direct replacement for the legacy SM-2 Buoy Marker Light?

Yes, the SM-3 meets all the same approvals the legacy SM-2, and also is approved to the international MED requirements. The brackets mounting hole locations are identical allowing for a quick and easy retrofit. Lastly, the new SM-3 using 2 AA Lithium batteries which is a lot more cost effective and easier to purchase than the legacy SM-2 which required the older lantern style batteries which are almost obsolete..

Q: I don’t see any buttons or switches, how do I activate the SM-3 Light?

The SM-3 has a built-in Gravity Switch, simply turn the SM-3 180 degrees so the LED Lamp is pointing towards the sky and the light will automatically activate and start strobing. To deactivate, simply turn the SM-3 so the LED Lamp is point towards the floor and the light will deactivate.

Q: Are batteries included? If not, what batteries does it require?

To ensure the product ships Non-Hazmat, no lithium batteries are included. The light simply requires 2 AA L91 Lithium batteries.

Q: How many buoy marker lights am I required to have on my vessel?

Regulations require that no less than half of your required buoys must be equipped with a certified buoy marker light. Minimum carriage requirements are based on the length of the vessel and can range from a minimum of 4 to a minimum of 15 lifebuoys with self-igniting lights per vessel.

Q: If I use the light in an emergency, do I need to replace the entire light?

No, once used, you must replace the 2 AA L91 batteries. MED requires the light to be replaced every 5 years.


  1. This SM-3 lifebuoy self-igniting marker light seems to be a highly effective and reliable solution for emergency situations on the water. The automatic activation and 360° visibility for over 2 miles is impressive, providing peace of mind for those in need of rescue. The fact that it operates for over 40 hours even at higher temperatures and floats upright in all conditions makes it a superior option compared to other disposable lifebuoy lights on the market. The user-replaceable batteries add to its durability and longevity, making it a worthwhile investment for anyone in need of a COB light

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