Garmin, Raymarine, and Simrad enclosed radars compared, part 2

Part 1 of my radar comparison generated a good discussion about the results and highlighted some opportunities to get back out on the water and complete some additional testing. I’m back with part 2 and the results of that additional testing. I’ve been able to test some additional scenarios, different settings, and more features of all three radars.

Gain on Garmin Fantom 18x

Unlike the other two radars, Garmin’s auto gain settings can be set to low or high. By default, the harbor preset uses auto low gain. For the first set of testing, I didn’t override any of the defaults of the respective presets, except for range, so that all screenshots matched.

This time around, I did change the Fantom 18x to auto high. The vast majority of this round of screenshots are in auto high. I did see some exaggeration of targets with higher gain, but overall, I think it’s an improvement. The screenshots above show auto high (on the left) and auto low (on the right) in nearly the same position.

Downtown Fort Myers round 2

This comparison is very similar to one from part 1, but this time with the Garmin in auto high gain. Also, you may have noticed I made a mistake by leaving the Simrad in its offshore preset rather than harbor. Although the Halo 20+’s performance may be slightly compromised, it still shows quite well. In fact, I think I’d still rank its return first, followed very closely by the Fantom and then the Quantum 2.

Dual-range

The Garmin Fantom 18x and Simrad Halo 20+ both offer dual-range capabilities. The Halo 20+ presents the two virtual radars as nearly entirely separate units. Each virtual unit can be powered up and down individually and all adjustments except rotational speed can be independently controlled. Garmin doesn’t create two virtual radars, but does allow nearly all parameters to be adjusted individually.

Bird mode

The Garmin and Simrad radars both offer bird mode. Circling birds are an indication of bait fish forced to the surface by larger predator fish. Those predators are often just what anglers are after. So, the idea is that if your radar can help you spot birds, you can put yourself on fish. I spent a while trying to tune both the Simrad and Garmin units to show me birds with very little success. One time, I got a few fluttering returns from a large flock of birds. Overall, I got the impression that the relatively low power — compared to larger open arrays, whether solid-state or magnetron based — of the enclosed arrays makes detecting birds a reach.

Radar overlay

Some boaters swear by radar overlay as a great way to maintain situational awareness. I’ve never found it particularly helpful and believe I miss many more radar returns in overlay than I do on a traditional scope. I suppose it all comes down to personal preference. But, I found a big difference in the ease of interpreting the returns from each radar unit when overlayed on a chart. The Raymarine and Simrad returns were both easy to spot and pretty clear. In contrast, my GPSMap 943xsv defaulted to a blue color palette for radar overlays. I found this color very difficult to spot.

Although the default blue was tough for me to spot, there are options. Fortunately, the color is selectable. I’ve selected red in the screenshot above, and it’s much easier to see.

MARPA and AIS display

When paired with a heading sensor, each of the three radar units supports MARPA or miniature automatic radar plotting aid. MARPA provides information about the speed, heading, relative bearing, distance, closest point of approach (CPA), and time to closest point of approach (TCPA) for tracked targets. For my testing, all three radars and displays used the NMEA 2000 heading output of a Garmin MSC 10 satellite compass. I’ve found this compass to provide rock-solid heading data, so I think the displays were all getting good heading and position information.

As you can see in several of the screenshots above, MARPA and AIS symbols are often overlayed directly on top of each other. The two technologies complement each other and provide confirmation of the data each provides. For AIS equipped vessels, I typically didn’t find it necessary to acquire them via MARPA. But, it’s not uncommon to see AIS targets with incorrect heading data. In those cases, acquiring the target via MARPA provides correct heading information on the vessel.

All three radar units occasionally had trouble providing accurate speed and heading numbers. The snippet above from the Garmin radar shows speeds varying from a relatively accurate 5.2 mph all the way up to over 25 mph. The target tracked in the video is the Tug Catherine from the previous set of screenshots. Safe to say, the tug and barge weren’t actually traveling at 25-plus miles per hour! In addition to these errors, I watched all three radar units struggle to track MARPA targets around large fixed objects. This was especially acute as tracked targets passed under bridges. I often watched the MARPA target circle move from a moving boat to a portion fo the bridge as the boat passed under the bridge.

Raymarine doppler presentation

In my first comparison entry, I noted that Raymarine is the only one of the three radars to change the presentation when doppler mode is enabled. I only included a screenshot of the white doppler color palette, not the full-color one. As you can see above, even when the full color palette is selected, the colors are more muted, and to my eye, there’s less clarity in the non-doppler returns displayed. I’m hopeful a future update might allow the same presentation on Raymarine systems.

Final thoughts

I’ve enjoyed the conversation generated by my first comparison entry. If there’s anything I haven’t covered above that you’d like to see, please speak up in the comments below. Unfortunately, I wasn’t able to cover echo trails as I would have liked. I collected quite a few screenshots of each radar’s echo trails but I wasn’t happy with them. I plan to try again the next time I get out on the open water.

My final thought after spending many hours comparing these radars is this: There are differences in how each radar unit perform at different functions and in different circumstances. But, in any of these situations or circumstances, I would confidently go to sea with any of these units.