| FAQ – Frequently asked questions
Frequently asked questions about our products
Do you have a question about one of our products? Take a look at our FAQ, you will often find the right answer here.
FAQ: AIS MOB Rescue Transmitter
An AIS MOB (Man Over Board) rescue beacon is a personal distress signaling device that is activated automatically or manually in the event of a person overboard emergency. It transmits the GPS position via AIS to nearby vessels and—in the DSC version—directly to VHF radios.
• AIS MOB: Locates the overboard victim via AIS within approximately 5–10 nautical miles.
• PLB (Personal Locator Beacon): Transmits distress signals via satellite (worldwide, longer rescue times).
• EPIRB: For ships, also transmits via satellite, triggers international rescue chains.
The range is approximately 5–10 nautical miles, depending on the antenna height and conditions. AIS signals are received by all nearby vessels with an AIS receiver.
Yes, an AIS MOB transmitter works with any AIS-enabled chartplotter or PC software that can display AIS MOB messages. A compatible VHF radio is required for DSC alerts.
Depending on the model, it can be activated manually at the push of a button or automatically when the life jacket is inflated.
The transmission time is usually 24 hours after activation.
Certified AIS MOB transmitters are waterproof (IP68 or higher).
Most AIS MOB transmitters are not self-floating – they require a buoyancy aid or must be attached to a life jacket. The only exception is the easy2-MOB (and its predecessors, the easyONE and easyONE-DSC). All Weatherdock rescue transmitters are self-floating without a buoyancy aid.
AIS MOB devices generally do not require official registration. However, if DSC functionality is used, an MMSI number must be programmed.
The battery typically has a lifespan of 5–7 years. Replacement should only be performed by an authorized service partner.
Yes, many devices have a test function that doesn’t send an emergency call. This allows you to check functionality and battery life.
In an emergency, an AIS rescue transmitter conforming to the latest standards immediately sends a “MOB distress call” using two parallel signals:
- AIS – GPS position data including course and speed to all vessels within range.
- DSC – Distress call with the current GPS position to previously stored vessels (closed loop), then automatically to all vessels and coastal radio stations (open loop).
This means: An AIS rescue transmitter from Weatherdock ensures that your distress is quickly identified, clearly located, and immediately transmitted to all relevant rescue services – for maximum chances of survival at sea.