First, let me apologize to MarkofSeaLife. I said that his opinion is too negative, and that was poor wording that could be thought of as "denigrating." I should restate this as my opinion is less negative than his. I have no dispute with his claim that having a full AIS transponder is extremely important in the ocean. The ability to have your vessel seen by others is extremely valuable in the ocean, especially at night or when singlehanding and taking an occasional nap while the windvane takes over. It also valuable in inland waters, though not as much.
However, given a choice between having an AIS receiver and no AIS at all, the AIS receiver still provides significant benefits that are worth considering. It has been 2 years since I priced out a full class B transponder vs. the receive-only options, but at that time it was much more economical to replace my dying VHF radio
with the SH 2150GX VHF
/AIS receiver. For me, this was the best balance of economy with my needs for the area where I sail. Others who sail elsewhere may have different needs, and the price of transponders may have come down since then (as is the case for all electronics). But I do disagree with any blanket statement that an AIS receiver is "not worth it." It may not be worth it for some, but for others it may meet their needs in an economical way.
Finally, I also disagree with blanket statements that cell phones and tablets are just "toys." While I consider the MarineTraffic site to be unsafe for navigation (whether viewed on a cell phone app, tablet app, laptop website, or supercomputer for that matter), my beef is with the way they collect their data, not with the hardware that it runs on. Cell phones and tablets have become fully capable computers, and as software emerges that can run full-blown chartplotter
software with display of all NMEA devices (including AIS targets, DSC calls, and all the instrumentation outputs) they may become viable replacements for dedicated hardware when paired with sunlight viewable displays and waterproof cases. Last I checked, iNavX and Navionics
did not yet have these capabilities for full NMEA integration (aside from being a repeater for laptop software), but it may just be a matter of time before they (or more nimble competitors) offer it. It's already part of the offering from turnkey marine electronics companies, and over time the lower cost computer software offerings will have it too.
For example, I no longer use my automotive GPS
device. My android phone, running Google Maps with navigation does the same thing, but much better because of instantaneous wireless updates of maps and graphical overlay of traffic status. Point and shoot digital cameras are disappearing because cell phone cameras have improved to the point where the vast majority of people are happy with them, and they offer instantaneous uploads to social websites. Over time I think it is likely that cell phones and tablets could do the same thing for marine electronics, especially on smaller boats where compactness and portability are more valuable. But the software still has a ways to go - MarineTraffic definitely does not cut it for navigation.