With the cost of AIS receivers coming down rapidly, I recommend at least the receiver. You'll get a lot more data further off than with any form of electronics
. The IMO is requiring more and more boats, of lesser tonnage, to carry AIS transceivers and those are the ones the seem to have no one at the wheel
. Being able to call that freighter by name, IMO number, course, and speed can improve your chances of getting a reply. You can also use their MMSI number with your DSC VHF
to send a text message.
Unfortunately, radars don't seem to be dropping in price
as fast. ARPA can be integrated into the radar and may be able to output to your chart plotter. There is a mini-ARPA that tracks fewer than the required number for full blown ARPA radars at a lower price
In my experience, AIS&ARPA on a radar clutters it up too much for me. Same for radar overlays on the chart plotter.
Then there's the power cost. AIS receivers take about an amp/hour to run so leaving it on at night, or all the time, is doable in most smaller boat situations. Radar takes some power, even if yours allows intermittent transmit. If you have smaller battery
restrictions, or weak batteries, you may not be able to run the radar as often as you want; or need to. IMO, it's as waste of money
if you can't get full use out of something. Many cruisers use the radar at night to warn them of approaching "hard objects" and even in timer/intemittent sweep mode, power consumption
can be considerable.
My preference order:
(1) AIS receiver
(3) radar with ARPA
(4) AIS transceiver
(5) AIS overlay on chart plotter
Most of the boats I work on have a separate AIS transceiver and ARPA radars. Thoughtful installation
means a quick glance at the AIS display or navigation software to see what's going on.
Radar can be a real anxiety saver but it requires good target reflection to work well. Low lying atols, small boats, and low in the water
obstructions can be masked by sea clutter. However, in those dark night, furious rainstorms, when getting back to the harbor is important, nothing is as good as radar. Same for the unresponsive tanker or field of fishing
boats; you can test your course correction to see what'll happen on the radar before executing it.