I had been looking for a low cost alternative for Radio based AIS over web based AIS and this device is the best thing I have uncovered yet for low cost AIS. This is a “Socotran Net Locator”. It’s designed to attach to fishing nets and transmit their location so commercial fishing fleets can easily find and recover the nets. However it can be programmed with an MMSI number and details about your boat. It’s self contained and battery powered and from my testing on Triumph it works extremely well. It was picked up by my navigation apps which only use web based AIS so it’s being broadcast and then pushed up to the wider network as AIS does. It cost less than $100. The programming is tricky if you are not computer savvy as it was not obvious. It does use USB programming but the software is weak to say the least. For me it was worth a shot and saved me over $900 in a transponder cost.
I purchased direct from Socotran with no issues. Check this out if you’re looking for a low cost AIS radio based solution.