Em-Trak
Em-Trak B953 5W SOTDMA Class B AIS Transceiver with VHF Splitter
Best high-performance AIS solution for serious sailors seeking reliable vessel tracking.
The Em-Trak B953 is a powerful 5W SOTDMA Class B AIS transceiver designed for superior performance and reliability. It offers exceptional AIS receive and transmit capabilities, ensuring you see more targets at maximum range while consuming minimal power. The integrated VHF antenna splitter allows seamless sharing of your existing antenna without performance loss. Featuring a built-in, high-performance GPS receiver and the innovative FLEXI-FIT bracket system, installation is straightforward and secure. This globally certified unit provides robust connectivity options for easy integration into your marine electronics system.
$860.00
Owner Satisfaction
4.7
/ 5
Category Rank
2
/ 178
#2 in Marine Radios
Price vs Category Average
+72%
Above average
AIS Class
5
/ B (W SOTDMA)
Who it's for
- Offshore sailors needing maximum visibility to commercial shipping traffic
- Boat owners looking to minimize antenna clutter and installation complexity
- Captains wanting seamless navigation data on mobile devices and plotters
Who should skip it
- Budget-conscious cruisers satisfied with standard 2W CSTDMA performance
- Small boat operators with limited battery banks and power budgets
- Safety-focused mariners preferring redundant antenna systems for critical communications
Performance breakdown
Signal Transmission Power
The 5W SOTDMA output ensures your vessel remains visible in congested waters.
Installation Versatility
The FLEXI-FIT bracket makes mounting simple on almost any bulkhead surface.
System Integration
Broad NMEA 2000 and 0183 support connects seamlessly with existing marine electronics.
Antenna Efficiency
Integrated splitter maintains signal integrity without needing a secondary dedicated antenna.
Durability Rating
IPx6 and IPx7 certification provides robust protection against harsh marine environments.
GNSS Acquisition Speed
Multi-constellation support delivers a reliable position fix in under thirty seconds.
Key Specs
AIS Class
B (5W SOTDMA)
Power Output
5.0 Watts
Dimensions
150 x 115 x 45mm (H x W x D)
Ingress Protection
IPx6 and IPx7 certified
Supply Voltage
12V or 24V DC (9.6V - 31.2V DC range)
Connectivity
NMEA 0183, NMEA 2000, USB
GNSS Systems Supported
GPS, GLONASS, BeiDou, Galileo
Weight
415kg
Features
- Certified 5W SOTDMA Class B AIS
- Integrated VHF antenna splitter
- High-performance GPS receiver
- Ultra-low power consumption
- Easy and secure FLEXI-FIT mounting
- Global certification for wide usability
- Waterproof and shock protected
- Enhanced RF screening for clear signals
What customers say
Mariners highly regard the Em-Trak B953 for its superior reliability and ease of integration. Users consistently praise the SOTDMA technology for delivering excellent range and dependable transmission, even in busy areas. A key feature is the integrated VHF antenna splitter, which simplifies installation significantly by removing the need for a separate antenna while preserving strong VHF performance. Setup is generally straightforward, connecting easily to modern chartplotters through NMEA 2000. Despite its premium cost, the consensus is that the enhanced safety, robust build, and installation convenience justify the investment. This unit is strongly recommended for serious boaters prioritizing dependable performance.
Know before you buy
The 5W SOTDMA (Self-Organizing Time Division Multiple Access) technology provides higher transmit power and more frequent updates than standard 2W CSTDMA units. This ensures your vessel is visible at a greater range and maintains a more reliable signal in busy waterways.
No, the B953 features an integrated high-performance VHF antenna splitter. This allows you to share your existing VHF radio antenna with the AIS unit without compromising signal quality or performance.
The unit offers versatile connectivity, including NMEA 2000, NMEA 0183, and USB. This allows for seamless integration with most modern chartplotters, multifunction displays, and PC-based navigation software.
Yes, the B953 is IPx6 and IPx7 certified, meaning it is fully waterproof and protected against heavy seas and temporary immersion. It is also shock-protected, making it durable enough for demanding marine environments.
The FLEXI-FIT bracket is designed to make installation simple and secure. It allows you to mount the transceiver quickly on flat surfaces or bulkheads without needing complex tools or custom mounting plates.
The B953 includes a built-in, high-performance 72-channel GNSS receiver that supports GPS, GLONASS, BeiDou, and Galileo. It uses a standard TNC connector, so you can easily attach an external GPS antenna if your installation location is below deck or shielded from the sky.
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