Sea Marshall® ‘SOS’ Man Over Board Systems

Base Units - a device that receives radio signals from one or more Alerting Units to indicate that a person using an Alerting Unit has fallen over board. The Base Unit can be either an MOB Alarm Only, the Sea Marshall® Crewguard or an MOB Alarm with Locating Function, the Sea Marshall® SARfinder®

Learn the Basics of a Maritime Survivor Locating Device

New SOS Capability The Sea Marshall® ‘SOS’ Alerting Units give you the full support of the Search & Rescue Authorities (121.5 MHz Homing), world-wide, should you need it.

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SARfinder MKII Fixed Dual Band Fixed Directional Finder Continuously Monitors for a Signal from a Sea Marshall® Alerting Unit

CrewFinder Fixed Radio Direction Finders RT-202 RT-300 RT-500

CrewGuard CG 121 MKII Portable Man Over Board Alarm only with optional Autodialler & External Antenna for remote unmanned installations

The system has two main components which interact with each other to create the ‘Sea Marshall® Man Over Board System’.

Worn by each crew member there is a miniature ‘SOS’ MOB Alerting Unit (Personal Locator Beacon), robust, fully automatic miniature radio transmitter designed to be discreetly worn around the neck or incorporated into a lifejacket, immersion suit. In the event of a crew member falling over board, within approximately 15 seconds, their Sea Marshall® ‘SOS’ Alerting Unit will automatically transmit a signal on 121.5 MHz, the International SAR homing frequency. 

At the other end of the MOB system we have the Sea Marshall® ‘SOS’ Base Unit. The Base Unit can be one of two options; it can be either a MOB alarm only, the Sea Marshall® Crewguard. Or it can be the dedicated Man Over Board Alarm and Radio Direction Finder called the Sea Marshall® SARfinder®. This raises the alarm and gives the Direction of the MOB on its high visibility, fully waterproof electroluminescent backlit display panel.