The ACR HydroFix is the hydrostatic release unit for a Cat I EPIRB housing. It releases the beacon at a depth between 1.5 and 4 meters. The HRU must be replaced every two years.
The component that actually releases your EPIRB when the vessel sinks
The ACR HydroFix is the hydrostatic release unit found in a Cat I EPIRB housing. At a certain water pressure, the mechanism releases the beacon so it can float to the surface and start transmitting. The release occurs at a depth between 1.5 and 4 meters.
What makes the HydroFix special is its patented rod system. There is no battery involved, no blade, and no pyrotechnic charge. As a result, there is less that can break or fail when it matters most. The HydroFix works with the Sea Shelter, Sea Shelter 2, Sea Shelter 3, and Sea Shelter 4 housings.
Important to know: this is a dated component. It must be replaced periodically, even if it still looks good. Write the installation date on the part itself with a permanent marker, as this is what you will use to track when it is due for replacement.
Why choose the HydroFix HRU?
Patented rod system: no battery, blade, or pyrotechnic charge that can fail
Release between 1.5 and 4 meters: the beacon is released before the vessel is too deep
Fits the entire Sea Shelter series: from Sea Shelter through to Sea Shelter 4
Easy to replace: the housing features a quick-release mechanism
Factory tested: every unit is checked before shipment
Who is this product for?
This component is required for anyone with a Cat I EPIRB setup on board. This is not optional: without a valid HydroFix, the housing will not release the beacon, and in practice, you have a Cat II setup without realizing it. Also required for a new Sea Shelter 4 housing with part number 2832, as the release unit is not included with it.
What are the benefits for you?
Your Cat I setup remains operational: an expired HRU makes the automatic release unusable
No battery to monitor: the mechanism works purely on water pressure
Quick to replace: maintenance that you can schedule yourself
Comply with requirements: a valid HRU is part of your safety equipment inspection
Write the date on the component with a permanent marker during installation
Production date
Stamped on the bottom, e.g., MFG.0622 for June 2022
Replacement interval
Every two years, as prescribed by ACR in their documentation
Required for
Sea Shelter 4 housing 2832, as it does not include an HRU
Important
Without a valid HRU, the automatic release of a Cat I setup will not work
Frequently asked questions
Why do I need to replace the HydroFix if it still looks fine?
Because it is a dated safety component. The mechanism must release at exactly the right water pressure after years of exposure to salt, sun, and temperature fluctuations. For this reason, a fixed replacement interval applies, regardless of how the component looks.
There is no date on my HydroFix, now what?
You write the installation date yourself on the part with a permanent marker. If there is nothing, look at the stamped production date on the bottom. If in doubt, replacement is the wisest choice, as an expired HRU makes your Cat I setup practically worthless.
Can I replace the HydroFix myself?
The HydroFix is a replaceable component and comes with its own installation manual. Pay close attention to the warning in the manual: the HRU keeps the ejection spring under tension, so you must hold that spring in place while replacing the unit. If you are in doubt, have it done by a service point.
Does the HydroFix fit every Cat I housing?
It is intended for the ACR Sea Shelter series, i.e., Sea Shelter, Sea Shelter 2, Sea Shelter 3, and Sea Shelter 4. For housings from other brands, you need a different part.
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