AIS OVERLAY · CLASS B
AIS Basics for Recreational Boats
See what AIS tells you, understand the difference between a receiver and a Class B transponder, and learn how AIS complements radar for safer traffic awareness.
AIS Receiver vs Transponder
Two ways to use AIS — different capabilities, same goal: better awareness.
AIS receiver
Receives nearby AIS broadcasts so a compatible display can show vessel names, positions, speed, course and CPA/TCPA data.
- See other equipped vessels
- Does not broadcast your boat
- Lower-cost entry to AIS awareness
Class B transponder
Receives AIS targets and broadcasts your own vessel identity and position to other AIS-equipped traffic.
- See and be seen
- Useful in busy coastal traffic
- Strong fit for night, fog and shipping lanes
AIS vs Radar
Different technology. Better together.
AIS identifies vessels
AIS can show vessel name, MMSI, position, speed, course and CPA/TCPA for vessels that are transmitting AIS.
Radar shows objects
Radar can detect boats, land, buoys and weather returns even when those targets are not transmitting AIS.
Best practice: AIS does not replace a proper lookout, radar or VHF communication. Use the tools together when available.
Build the rest of the electronics path
Shop the related gear or continue into the Marine Guides hub.
AIS is a supplemental awareness tool. Follow manufacturer instructions, navigation rules and official Coast Guard guidance.