The Navico NAIS-300 is a full class-B marine AIS transceiver designed to display data on a compatible chartplotter, dedicated display, or on a PC with compatible software.
The NAIS-300 is housed in a waterproof plastic 5.1-inch by 8.2-inch by 2.5-inch black box (actually grey) that weighs just over 21 ounces. It is designed to mount on a flat surface either vertically or horizontally.

Navico NAIS300
The unit communicates with a chartplotter display via SimNet or NEMA0183-HS. SimNet is Navicos proprietary high speed data bus network compatible with NMEA2000. The NMEA0183-HS data transfer speed is 38,400-baud instead of the slower 4800 baud used by regular NMEA0183 units.
Bottom line here is you can only connect this AIS unit to a chartplotter capable of communicating via NMEA0183 high-speed protocol. Data transfer to a PC is via an RS-232 connector. For our testing we used both the NMEA0183-HS connection to interface the NAIS-300 with a Raymarine A50D chartplotter and the RS-232 link to connect to a Windows-based PC. Both connections functioned properly. We did not test the SimNet connection.
Four LED lights provide status information on Navico NAIS-300 functions. To put this unit in Silent mode (turning transmissions off) requires installation of a momentary on switch connected to the transponder unit.
Installation
The unit needs to 12-volt DC power supplied. Be connected to its GPS sensor, a VHF antenna for signal reception and transmission, and connect to some sort of display. Electrical connections to the Navico unit are made with provided block connectors or with a SimNet plug-in connector. We tested using the block connectors.

Wiring the Navico NAIS300 to our test rig which used a Raymarine A50D MFD.
Installation of the Navico NAIS-300 is pretty easy. Youll need to mount the transponder box and connect it to DC power. Then youll need to mount the GPS sensor and connect it to the transponder box. Lastly, youll need to mount and connect a VHF antenna. Youll also need to make a data cable connection to your display of choice.
Even though the manual recommends a VHF antenna tuned specifically to the AIS frequencies we used a standard VHF radio antenna and found the unit functioned well with no issues. You should be aware when connecting this unit to a chartplotter that it will need a NMEA0183-HS port to work properly. To connect to a PC youd use the provided RS232 (serial





