Choosing Category 1 EPIRBs Correctly

There are primarily two types of EPIRBs that you should be familiar with: Category 1 EPIRBs and Category 2 EPIRBs.

The deployment of your Cat I EPIRB can occur in two ways: through manual release or via an HRU (Hydrostatic Release Unit).

The HRU is designed to automatically release the beacon when submerged in water at certain depths, ensuring the device floats free without crew intervention should a vessel sink.

Differences Between Category I and II

Key differences between Category I and II EPIRBs include their activation methods. Category I beacons are equipped with a hydrostatic release, intended for automatic operation upon submersion, while Category II beacons rely predominantly on manual activation.

When picking an EPIRB for your boat, consider factors such as the size of your vessel, the typical number of crew, and the voyages you plan to undertake.

Activation and Signal Transmission

In the event of a distress situation, you have the option to manually activate your Category I EPIRB.

This is done by physically deploying the beacon and activating it according to the manufacturer’s instructions.

If you’re unable to release the EPIRB manually, the Category I beacon is equipped with a hydrostatic release unit (HRU), allowing it to float free.

The HRU releases the beacon from its bracket when submerged in water, often at a depth of 1.5 to 4 meters. Upon deployment, they are automatically activated and begin transmitting the distress.

Once activated, either manually or automatically, the EPIRB transmits two crucial frequencies.

The primary 406 MHz distress signal is relayed to satellites and ground stations, which assists in determining your location almost anywhere in the world.

The secondary frequency, a 121.5 MHz homing signal, is a lower frequency that local search and rescue teams hone in on as they approach your position, ensuring precise and timely rescue efforts.

Advanced EPIRB Technologies

EPIRBs have evolved significantly with the integration of advanced technologies like AIS and GNSS, ensuring improved accuracy and speed in search and rescue operations.

Your Category I EPIRB now likely includes both Automatic Identification System (AIS) and GPS functionality.

This integration significantly reduces the search area, thus speeding up rescue response times.

With a GPS, the position fix is much more rapid and accurate.

Modern EPIRBs offer enhanced networking and connectivity features.

The addition of Return Link Service (RLS) confirms that your distress signal was received, which could be invaluable for your morale should you have to ever use your EPIRB.

Products like the GlobalFix V5 illustrate the strides made in connectivity that bolster your safety on the water.

The Global Navigation Satellite System (GNSS), including systems like GLONASS and satellites with global coverage, has been fundamental in improving EPIRB distress signal detection.

This comprehensive network allows for near-immediate alerting of search and rescue services regardless of your location worldwide.

Enhanced satellite connectivity ensures that your emergency is pinpointed quickly and accurately, leveraging the robust GNSS infrastructure.

Frequently Asked Questions

Yes, certain vessels are required by law to carry a Category 1 EPIRB. This generally applies to commercial vessels and passenger ships of certain sizes that operate in open waters. They must adhere to international safety regulations, including those outlined in the Safety of Life at Sea (SOLAS) Convention.

Ocean Signal offers the RescueME EPIRB1 Pro and EPIRB3 models, notable for their compact design and long battery life. The EPIRB3 model stands out with features like AIS, NFC, GPS, and Return Link Service, making it a highly specified choice for leisure boaters​​.

McMurdo’s SmartFind G8 AIS EPIRB includes an AIS transmitter for local vessel location information, enhancing the chances of rescue. It features a 77-channel multi-constellation GNSS receiver, manual/automatic activation, and a long operational life.

I’m the founder and chief editor here at Sailing Savvy. I spent a decade working as a professional mariner and currently, I mix those experiences with digital publishing. Welcome, and I hope that we can be the hub you need for safe passage.