AIS Class A vs Class B is one of the most important comparisons when choosing an AIS system for your boat. The main difference lies in transmission power, update frequency, and intended use.
Class A AIS is designed for commercial vessels and SOLAS compliance, while Class B AIS is typically used on leisure boats and smaller commercial vessels.
This guide explains the differences between AIS Class A and Class B systems, helping you choose the right option for your vessel and application.
What is AIS Class A?
AIS Class A is designed for commercial vessels and is required under SOLAS regulations. These systems transmit at higher power and update position data more frequently.
- Higher transmission power (typically 12.5W)
- Fast update rates for real-time tracking
- Mandatory for large commercial vessels
- Full integration with onboard navigation systems
What is AIS Class B?
AIS Class B is designed for leisure boats and smaller commercial vessels. It provides effective tracking and visibility but at a lower transmission power and update rate compared to Class A.
- Lower transmission power (2W or 5W depending on model)
- Slower update intervals than Class A
- Suitable for recreational and small commercial use
- Easier installation and lower cost
Which is Better: AIS Class A or Class B?
The choice between AIS Class A and Class B depends on your vessel type, regulatory requirements, and how you operate.
- Choose Class A: If you operate a commercial vessel, require SOLAS compliance, or need maximum visibility and transmission performance
- Choose Class B: If you are a leisure boater or small commercial operator looking for reliable tracking and collision awareness
For most recreational boat owners, Class B AIS provides more than enough functionality while being easier to install and more cost-effective.
EM Trak AIS Class A and Class B Systems
F&C Marine supplies a full range of EM Trak AIS systems covering both Class A and Class B applications for commercial and leisure vessels.
- Class A AIS: EM Trak A200 for SOLAS and commercial vessel compliance
- Class B AIS (2W): EM Trak B921, B922, B923, B924
- Class B AIS (5W SOTDMA): EM Trak B951, B952, B953, B954
- Advanced AIS systems: EM Trak B400 and B200
Choosing the correct AIS system depends on vessel size, operating environment, and whether higher transmission power or regulatory compliance is required.
Conclusion
Understanding the difference between AIS Class A and Class B is essential when selecting the right system for your vessel. While Class A is required for commercial shipping, Class B provides an effective and practical solution for most leisure and small commercial boats.
Both systems improve safety, awareness, and collision avoidance by ensuring your vessel is visible to others and allowing you to track nearby traffic.
To understand how AIS works in more detail, see our AIS guide.