The ACR OLAS CORE is a small, portable, wireless Man Overboard (MOB) Alarm system that triggers an instant emergency alert, within 4 seconds of a MOB incident. The CORE provides coverage for vessels up to 50 ft and the OLAS EXTENDER is an available option to expand coverage for vessels up to 80 ft.  With the ability to connect to a total of 15 wearable OLAS Tag and/or OLAS Float-On transmitters, the CORE creates a virtual lifeline to your crew members and acts as your boat’s base station to monitor and alert the crew should one of the transmitters go missing.  The CORE can also connect with the ACR OLAS mobile app which, in the case of a MOB incident, provides easy to read directional screens with a bearing and trackback to the point where the alarm was triggered. The app also provides essential MOB position and procedure prompt screens, supporting the crew during the stress of a recovery operation.

Losing a crew member overboard is every boater’s worst nightmare. The ACR OLAS CORE gives boaters complete confidence that in the event of a MOB incident, the entire crew is alerted instantly and can take immediate recovery actions. Consisting of an easy to install base station that can be permanently mounted or used as a portable solution, the CORE communicates wirelessly with all connected OLAS transmitters at the same time.  Syncing transmitters is simple with a single button push that not only syncs the transmitter(s) with the CORE but also allows users to connect transmitters to the OLAS mobile app.


Important Extender Information

Please note we are currently working on an update for the EXTENDER module to fix the issue outlined below. We apologize for any inconvenience. For further information please contact

Estimated update release date 26th Nov. 2022.

Issue: Connection may be lost between the OLAS App and the CORE or GUARDIAN if an EXTENDER is used.

Please note the EXTENDER can continue to be used if the OLAS App is not required beyond the initial setup. Connection between the CORE or GUARDIAN and the EXTENDER is not affected.

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The CORE is your back-up for your back-up. Let’s face it, we all overuse our smart phones, and out on the water, they can overheat, run out of battery, and simply break. The CORE ensures your MOB situation is not solely reliant on your mobile device and thereby provides an additional level of security when paired with your ACR OLAS MOB system. The CORE works using the latest wireless Bluetooth 5 technology and in the event of a MOB incident, it triggers a loud built-in alarm and emergency light, providing both audible and visual cues to alert crew of the situation.

CORE Advantages

  • OLAS Integration

Any OLAS transmitting devices (OLAS Tags or OLAS Float-On LED Lights) within range can be tracked by the CORE, allowing freedom for the crew to move around the deck with total confidence that an early warning system will alert them instantly of a MOB incident, so a swift recovery can be actioned.

  • Connects to 15 OLAS Transmitters (OLAS Tags or OLAS Float-On LED Lights)

Connecting up to 15 OLAS transmitters allows the CORE to be used on onboard larger vessels. OLAS transmitters are not only relevant to tracking crew members, simply by attaching a transmitter to objects such as MOB flotation devices, the dog or a yacht tender, you can always be aware if something has gone missing. 

  • Portable / low power consumption – 5V USB

The OLAS CORE is a portable base station that is powered by a 5V USB power supply enabling it to be used on different vessels without requiring hard wiring.

  • Audible and Visual Alarms

An 85db alarm will sound to indicate an ACR OLAS transmitter has gone out of range and a high-power emergency red light will illuminate, offering clear visual indication of a MOB alert, whilst also acting as a light to illuminate the area to aid with recovery at night. The CORE can also be linked up with the OLAS app so that alarms can be placed in multiple locations on the vessel.

  • Integrates with the ACR OLAS Mobile App data and monitoring
    • Instantly records the GPS location of the MOB alert position, guides the user back to the location with clear directional screens, and advises on the correct mayday call procedure.
    • Monitors all ACR OLAS Transmitters that are being tracked and enables customized ID names for easy identification
    • Monitors battery level of all connected ACR OLAS Tags
    • Enables you to add/remove OLAS Tags and Float-Ons from the system
    • Provides the option to manually activate/deactivate the alarm system
  • Expand the OLAS CORE Coverage Area

An OLAS Extender can be used with the OLAS CORE to cover areas where the Transmitter signal may be blocked. This allows use on larger vessels up to 80ft and the ability to scale the system up as required.

  • System Feedback

The CORE clearly indicates how many OLAS transmitters are connected during the setup process.

Transmitters can be added/removed from the system either using the mobile app or through a simple integrated switching process.


ACR OLAS is a must have addition to your safety toolkit. It provides a simple and cost-effective safety solution for everyone on board including adults, children and even pets.         


Key Features:

  • ACR OLAS Free Mobile App Integration
  • Ultra-Bright Red LED Visual Alarm
  • 85 db Audible Alarm
  • Connect up to 15 ACR OLAS Transmitters
  • Waterproof (IP67)
  • Utilizes the latest Bluetooth® 5.0 Technology
  • Portable / Low Power Consumption – 5V USB
  • Expand system coverage from 50 ft. to 80 ft. using the OLAS EXTENDER


Additional information

Weight 1 lbs
Dimensions 9 × 9 × 5 in


ACR Product Number

PN 2984


3.6” (H) x 3.5” (L) x 1.5” (W)/92 (H) x 90 (L) x 38 (W) mm


3.88 Ounces (110 g)


Black and Clear


Press button once to turn on, all tags within 2 meters are tracked

Maximum Number of Connected OLAS transmitter

Connects up to 15 OLAS Transmitters (OLAS Tags and/or OLAS Float-On)

Power / Current

5V / 13-17mA

Visual Alarm

Red LED / 55 Lumens

Audible Alarm

85 Decibels

MOB System

Track up to 15 different OLAS transmitters with 1 phone/tablet.  OLAS Transmitters can be tracked by an unlimited number of phones/tablets (Bluetooth 4.1 Compatible).

The ALARM sounds within 8 seconds of a Man Overboard situation.  The system records the MOB location using your phone/tablets GPS and directs the boat back to the last known location for a quick and easy recovery.

Compatible with the ACR OLAS Guardian, Extender, Mobile App, Float-On, and Tag.

Mobile App

IOS and Android (Free Download)

  • Connect multiple OLAS transmitters to 1 phone or tablet
  • Connect 1 OLAS transmitter to multiple phones / tablets
  • Solo Mode (Text Message Alerts to Emergency Contacts with GPS coordinates)

Download the ACR OLAS App on the App store or get it on Google Play: Search ‘ACR OLAS’


For use with vessels up to 50 feet (15 meters).

Extend the coverage range on larger vessels with the ACR OLAS EXTENDER for coverage on boats up to 80 feet.


Upgrade your system with the ACR OLAS Guardian (Base Station with Alarm and Engine Kill Switch) and the ACR OLAS Extender (extends range of your MOB system from a vessel size of 50 ft up to 80 ft).




Yes (IP67)

Housing Material



Not Applicable


4.2 + 5.0


Recreational and Commercial Boating

Accessories (included)

USB Charging Cable


2 Years


FCC, RED, CE, RoHS 2.0



This product is warranted against factory defect in material and workmanship for a period of 2 (two)* years 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.

For further assistance, please contact our Technical Service Department at :


ACR Electronics, Inc.

5757 Ravenswood Road, Fort Lauderdale, FL 33312-6645


Telephone: +1 (954) 981-3333

Fax: +1 (954) 983-5087

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 WITH RESPECT TO THIS PRODUCT, except as otherwise expressly stated in the previous paragraph. The Company shall not be liable for consequential or special damages. In order to place the warranty in effect, complete the form in your account. 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:  EPIRB and PLB.

Can the Core or Guardian operate without the mobile app?


Yes, the Core and Guardian can setup, monitor and alert without requiring the OLAS mobile application. Through light indication on the switch and sound signals from the hub, the user can easily check the number of OLAS transmitters being tracked and the state of the device i.e. scanning, tracking, paused or alarming. The OLAS mobile app is only required as an additional tool to aid in setup and monitoring the OLAS system. The OLAS app also acts as an extra alarm and includes rescue screens to aid in MOB rescue including scripted Mayday call and Solo mode, an automated text message for use whilst on your own, within cellular range (minimum 2G or Wi-Fi required).


What is the difference between the Core and the Guardian?


The Core is a portable MOB alarm system which can be plugged into any 5V USB power socket. It has an emergency light and internal alert to indicate a MOB.


The Guardian is a hard-wired solution which can operate from 10-24V. The Guardian can be wired into a vessels existing kill switch, stopping the engine in a MOB situation. The same wiring solution could also be used to activate an external MOB alarm system. The Guardian has an emergency light and internal alert sound to indicate a MOB.


When an OLAS transmitter is switched on, will it automatically be tracked by the OLAS system?


No, if using the OLAS app, Core or Guardian action is required to start tracking the OLAS transmitter. Check the user guide for further instructions.


How should I maintain the Core?


Ensure the Core remains clean and dry. If it becomes wet, clean with fresh water, avoiding the charge port and dry ensuring no water is left in or around the charge port or buzzer. Keep the Core out of direct sunlight.


My boat is longer than 50ft, can I still use the Core or Guardian?


Yes, but it is likely you will need to add an OLAS Extender to the system which will allow use on vessels up to 80ft.


What is the maximum distance I can go from the Core or Guardian without triggering the alarm?


The distance can vary depending on where the Core or Guardian is installed and the material of the vessel. If the Core or Guardian is located centrally in a vessel effective coverage of a vessel up to 50ft can be achieved. If a transmitter is submerged in open water it will disconnect immediately even if within the 50ft range.


Can an OLAS transmitter leave the vessel without triggering an alarm?


Yes, but the OLAS system will either need to be in Pause or the individual tag will need to be in a paused state. To pause tracking of individual OLAS transmitters the OLAS app should be used. To pause the whole OLAS system either the OLAS app or the Core / Guardian hub can be used. 


When the OLAS system is paused, if an OLAS tag leaves the vessel and does not return can the OLAS system re-start tracking?


It is not possible for OLAS to restart tracking until all OLAS transmitters are back in range. If you try to restart tracking a triple beep sounds indication will occur from the hub. If the OLAS transmitter will not return the OLAS system need to be restarted. All remining transmitters will need to be brought back within 2 meters of the Core or Guardian hub within the 30 second start up.   


What should I do when an OLAS transmitter has set off the alarm and then been recovered back to the vessel? 


Bring the OLAS transmitter back within 2 meters of the Core or Guardian hub. If the Core or Guardian hub is still alarming press the button once to pause the alarm and then press the button again to restart tracking. 


How can I check to see how many OLAS transmitters are being tracked?

Press the switch on the hub once, it will then indicate the number of tracked OLAS transmitters with a sounds and light signal.


The alarm is not triggered when I put the OLAS transmitter into a bucket of water?


The OLAS transmitter needs to be submerged by up to 4 inches in open water. If submerged in a bucket the wireless signal can transmit out of the side and bottom of the bucket.


If I switch the OLAS tag off will this trigger the alarm?


Yes, switching the OLAS tag off is the same as disconnecting the OLAS tag by falling overboard or submerging it in open water. We recommend testing the OLAS system regularly.


What measures can I take to ensure optimal performance of the OLAS technology when using the Mobile App:


1. Do not connect other Bluetooth devices whilst using the OLAS app

2. Ensure the OLAS app is at least 1 meter from other RF transmitting devices

3. Select ‘Always’ for location access in your App settings

4. Allow notifications

5. Only 6 OLAS tags should be ON within range of the OLAS app

6. Avoid carbon, metal or water as this will block the OLAS data

7. Always check connections prior to setting off



What is the minimum phone requirement? 


iPhone 5 onwards / 3rd generation iPad onwards / Android 4.4+ / Bluetooth LE (The Bluetooth chip in some Android devices can vary, always check compatibility after purchase and return if not suitable).


What is the maximum distance? 


75 meters if in an open space. On a yacht we recommend up to 40ft. Always test the range limitations to avoid false alerts.


What is the maximum yacht size? 


We recommend up to 40ft. Always test the range limitations to avoid false alerts.


Does the tag transmit GPS? 


No, the GPS is taken from your mobile device running the OLAS app. It is recorded at the time of alarm, like pressing the MOB button on a chart plotter.


Where does the OLAS app direct back to? 


The app is always directing back to the last known location of the OLAS tag I.e. the point at which the alert sounded.


What is the battery life? 


If turned on and left on up to 4 months. Every time the OLAS tag is switched OFF/ON more power is used. On average around 3 months.


How many phones can use the OLAS app? 


The OLAS app is free of charge and will be updated regularly as and when technical advances are made.


Is the battery user replaceable? 


On the OLAS tag yes, it uses a CR2477. On the OLAS Float-On the battery is rechargeable.


How many OLAS transmitters can be attached to 1 phone? 


Up to 6 is recommended for Andorid devices and 8 for iOS devices to maintain a stable connection. No more than the stated number can be within range of the phone being used.


Can I use a mixture of OLAS tags and OLAS Float-On’s? 


Yes you can use both connected on the same app. They will automatically indicate which is which.


How do you identify different tags? 


When first purchased the tag or Float-on will have a number that will also be represented when it is seen in the app, the name of the tag or Float-On can then be changed. To revert to the number the OLAS app needs to be deleted and reinstalled.


How can I monitor the battery? 


The OLAS tag indicates its battery status in the OLAS app. If the app is running when the level gets below 10% is indicated in the OLAS app.


The OLAS Float-On has battery indication using the traffic light system. When a charge is necessary it will illuminate solid red.


What happens if there are more than 6 OLAS transmitters around 1 device?


The 7th OLAS transmitter may push one of the previous 6 from the list causing a false alert. For this reason, only 6 devices can be used within range of the OLAS app.


What are the optimum OLAS app settings to avoid false alerts?


‘Always’ should be selected in your App settings and notifications should be allowed.


Can I have a different Bluetooth device connected?


No. If using the OLAS app it should not have any connections with external Bluetooth devices.


What is the proper method for testing my OLAS TAG or OLAS FLOAT-ON Transmitter in order to provide the most accurate representation of how the mobile app will communicate with the transmitter in a man overboard (MOB) scenario?

1. Only test 1 OLAS TAG at a time

2. Ideally carry out the test on land

3. Ensure the OLAS TAG you are carrying the test out with is either switched off to cause the alert or fully out of range by submerging in at least 6 inches of open water. Leave the TAG submerged for the entirety of the test. If the TAG is removed from the water or switched back on whilst still in range of the mobile device the TAG will reconnect and OLAS will resume normal tracking. Placing the TAG in a sink or glass of water will not work.

4. You will see TAGS status change from Green reading “Immediate,” “Near,” or “Far” to Red reading “Paused” to “Unknown”

5. After 8 seconds the alarm will sound

6. Accept the alarm and then walk away from the TAG. A searching icon will appear to indicate that you are still within 20 meters of the point of loss and would be within visual contact of the man overboard (MOB)

7. Having walked approximately 20 meters from the TAG, the searching icon will change to an arrow pointing back towards the point of loss. Continue walking for a further 20 meters, this will simulate the vessels onward movement prior to stopping and changing direction to perform a search and rescue 

8. When you reach around 40 meters from the point of loss turn around and follow the arrow

9. Once back within 20 meters the searching icon reappears, this would indicate when you should initiate a search protocol based on the wind and tidal conditions

10. Once back within the 20 meters either switch the TAG back on or remove it from the open water and it will automatically reconnect, cancelling the alarm. When this occurs you know the TAG is back within range