Solid state radomes compared, part 3 – Furuno checks in

This article is supposed to be a thorough comparison of how Furuno’s DRS2DNXT compared to the other radars I’ve tested. Unfortunately, testing multiple radars on a 22-foot boat is challenging. The most recent challenge included snapping a freshly made mount before I was able to get offshore with the setup. The bad news is, I wasn’t able to complete all my testing scenarios. The good news is, I still have the radar unit and I’m working on more permanent and robust mounting options. But for now, here’s what I’ve learned.

	Size	Weight	Output power	Beam Width	Max RPM	MSRP
Furuno DRS2DNXT	19-inches	14.3 lbs	25 watts	5.2 degrees	48	$2,295
Garmin Fantom 18x	18-inches	14 lbs	50 watts	5.2 degrees	60	$2,199
Raymarine Quantum 2	18-inches	12.4 lbs	20 watts	4.9 degrees	24	$2,310
Simrad Halo 20+	20-inches	13 lbs	25 watts	4.9 degrees	60	$2,299

This is the third installment of this series. The first two installments can be found here and here. I plan to continue comparing the features, interfaces, and capabilities of Furuno’s DRS2DNXT, Garmin’s Fantom 18x, Raymarine’s Quantum 2, and Simrad’s Halo 20+ radomes. Interestingly, I observed very little correlation between “better” specs and better performance. Radar performance has long been a mix of science and art and I don’t see anything contradicting that in these results.

Tales of mounting woe

Indulge me while I give a quick rundown of the trials and tribulations of the mounts I’ve used. Nautical Creations made me a pair of brackets that worked well for a while. But, I think the combination of a relatively small, single clamp and rough water meant that both brackets started slipping. I tried to make that better by tightening the screws, however, all I accomplished was distorting the relatively soft aluminum of the clamps.

So, I needed a plan b and possibly c. It seems clear the only lasting solution is an option that clamps in multiple places and relieves a single mount of all the load. I’m working with Nautical Creations on a low-profile arch with multiple modular mounting locations for cameras, radar units, or whatever other random items I might test. But, in the meantime, I wanted a way to test the Furuno radar before the arch is ready. I’ve used Shakespeare 1″-14 rail mounts with various platforms effectively. In exchanging photos with the fabricator, he saw one of Shakespeare’s mounts and suggested we build a mount with one of them. That arrived recently and so I quickly bolted it onto the rail of the t-top and hit the water.

As you can see, I found a weak spot in this mount as well. It’s quite obvious I was asking the mount to do a job way outside its intended purpose. That job simply put too much stress on that relatively small casting where the 1″-14 mount meets the clamp body. So, my testing was aborted and now it appears to be time to concentrate on the arch. In the meantime, let’s take a look at the testing I’ve been able to complete.

Testing results

I came into these tests expecting a lot from Furuno’s radome. Furuno has, in my opinion, a well-deserved reputation for making high-performance radars. Looking at a Furuno radar scope, I feel there’s often something about what you see that just looks better. Let’s see if the DRS2DNXT lives up to that reputation.

As I mentioned, I can really only fit three radars on the boat so I had to pick one unit to leave off this time around. I picked the Raymarine Quantum 2 to leave off. The Quantum is the oldest radar of the four and I think it’s reasonable to expect we may see a new unit relatively soon.

Previously, in this same area, I’d felt that the Simrad was the best-performing unit. This time around, the Furuno and Simrad radars are performing at similar and very high levels.

Both radars do an excellent job representing the returns around them. There’s very little distortion and the returns seem consistent and clear. If I work hard to find a difference between the two, I can find one in the way that Lofton’s island is depicted just past the bridge forward and to starboard of the boat. I think the Furuno radar is drawing it slightly more accurately. The island’s current configuration doesn’t quite match what you see in Google Earth as that aerial picture was taken pre-Hurricane Ian and most of the docks are now gone.

3nm zoom scale

At the 3-mile range and in a more open portion of the river we have another opportunity to compare the performance of the radars. To my eye, Furuno is the least aggressive with gain and target expansion, Simrad is in the middle, and Garmin is the most aggressive. I think it’s a Goldilocks situation with Simrad striking the best balance. The difference between the Simrad image and Furuno’s is pretty small.

But, I do see differences like the Halo 20+’s clear returns of the second bridge aft of the boat. Even with gain at auto low, the Fantom 18x exaggerates the returns. In contrast, the Furuno doesn’t fully show the second bridge. With each of these tests, I wonder if the radomes’ positioning could influence the results. In this case, the results don’t seem to correlate to relative position. The Garmin is mounted on the center, forward, and the lowest. The Simrad is on the aft starboard side and elevated 8 inches. The Furuno is aft on the port side and elevated 16 inches.

True ARPA

All the radars in this comparison can utilize Doppler technology to highlight returns moving towards and away from the vessel in appropriate colors. The Halo 20+ can automatically acquire targets in two designated areas of the radar scope. But, the Furuno is the only radome that boasts what I would call true ARPA. As soon as the radar is powered on, it starts acquiring targets.

It’s interesting to note that although I call it true ARPA, Furuno’s product descriptions refer to it as Fast Target Tracking. Overall, I’ve noticed all manufacturers seem to be cautious about what they describe as ARPA. In the IMO world of commercial navigation equipment, ARPA has specific meanings and requirements, so their caution is probably well placed. However, the DRS2DNXT delivers everything I think of when the term ARPA is used.

In my testing, limited to the river owing to my bracket difficulties, I sometimes saw the unit over-identify targets. I suspect the sheer number of returns, many moving, serves to confuse the radar. Especially since many of the returns may be cars either close to the water on shore, or on bridges crossing the water.

I should reiterate that my testing of target acquisition is hampered by only having the opportunity to test on the river. But, I’m still liking what I’ve seen thus far. In earlier entries in this series, I’ve noted suspect data from MARPA target tracking. Overall, what I saw from the Furuno was very good. Occasionally, when the scope got crowded and there were lots of moving targets, I did see inaccurate behavior. But, most of the time I saw very good results and highly accurate information as confirmed visually and with AIS.

Final thoughts

This comparison is less complete than I’d like. Until I am able to get the boat off the river and into open water, the comparisons won’t be complete. Once that’s done, there’s much to compare in how the radars and displays implement various features. That notwithstanding, Furuno’s performance thus far has been impressive and certainly lives up to its reputation for class-leading radar performance. So, as with previous entries, the series isn’t done and I’ll be back with more.