Halo24 First Impressions

[Dockhead]

I replaced my trusty 4G radar with a Halo24, and did my first passage with it.


I expected a dramatic improvement in performance, as the Halo radars combine pulse compression radar with the CW radar of the 3G/4G radars, using pulse for longer ranges, and CW for closer ranges.



Also the antenna is much larger -- this is a 24" vs 18" radar.


First impressions are good. Immediately noticeable is a dramatic increase in range -- I get vivid returns from high land features more than 50 miles away.


This is useful for radar navigation, with the caveat that I never found the range of the 4G radar to be inadequate at all. In fact, I found its performance at longer ranges (but much less than 50 miles) to be very respectable.


I do not notice, so far, any better target discrimination or bearing discrimination, although I expect that from the larger antenna. The close range performance seems to be similar to the 4G's.



I have not yet played with the bird mode, weather mode, etc., but the addition of the pulse radar should make this radar much better for tracking weather. Not that there was anything so bad about the 4G radar with weather.


MARPA seems to work better, but I didn't track more than one target so small sample size.


What I'm really pleased with are the new Zeus 3S plotters. I've used these before -- I put them on my friend's Discovery 67 which I crossed the Atlantic on two years ago. But comparing them side by side with the older Zeus plotters underlines the big increase in resolution and brightness of the screen. There are more hardware buttons which is also an improvement. The knob is some special very high quality job which feels expensive and good. And I'm loving the C-Map high resolution bathymetry, and the bottom contour display. On the minus side, no USB ports, only one Ethernet port.


I have not yet installed the new Zeus at the nav table, just the one at the helm. It's interesting that the ancient non-touch Z8 Zeus plays nicely with the new Zeus 3S, sharing waypoints, routes, etc., and actually working fine with the Halo24 radar, operating it perfectly except for the special modes. If I had known, I would not have replaced the Z8 at the helm.

[Mal Reynolds]

Thank you for the review. I would certainly expect better target discrimination. Let us know if you think it's any better with more use. Also with incoming squalls.

But never mind about all that. Does it look better on your mast?

[Dockhead]

Originally Posted by Mal Reynolds

Thank you for the review. I would certainly expect better target discrimination. Let us know if you think it's any better with more use. Also with incoming squalls.

But never mind about all that. Does it look better on your mast?

Well, my boat is severely optimized for upwind work, no solar, etc. etc. so I care a whole lot about drag.



The Halo24 dome is larger so unpleasantly, to my eye, looks like more drag. And 10 meters above the waterline the wind is really working -- you really want to be streamlined there.

[Mal Reynolds]

Interesting. I also worry about lee shores.

I"m moving the radar from an aft pole to the mast in part to help with windage, but at a small hit to righting moment, although the new setup is quite a bit lighter. I will also lose a tilt ability but I don't often run into both strong breeze & fog. More likely I'll be in light air or motoring.

I recently had to decide between the Halo20+ and the 24. I have a pretty beefy mast section so was worried the 20 would look a bit unserious. Crazy the factors that come into play when making decisions.

If I had a sub-50' boat or a racing boat the 20 would be an easy decision if going with Navico.

[Dockhead]

Originally Posted by Mal Reynolds

Interesting. I also worry about lee shores.

I"m moving the radar from an aft pole to the mast in part to help with windage, but at a small hit to righting moment, although the new setup is quite a bit lighter. I will also lose a tilt ability but I don't often run into both strong breeze & fog. More likely I'll be in light air or motoring.

I recently had to decide between the Halo20+ and the 24. I have a pretty beefy mast section so was worried the 20 would look a bit unserious. Crazy the factors that come into play when making decisions.

If I had a sub-50' boat or a racing boat the 20 would be an easy decision if going with Navico.

I wouldn't worry about righting moment. Not enough weight to matter, especially if you have a "beefy mast section".


I'm not sure there will be any difference in windage, either. You lose the pole, which is good. But higher up, there will be more drag. On the plus side, higher up is better for radar performance other than really close in. It's particularly better for being able to pick targets out of sea state, and this is important.



Nor is the tilt a factor. There's no noticeable degradation of radar performance at a 10-15 degrees of heel, with these radars, I've found, and by 20 I'm worried about other things.



As to 20 vs 24, if you don't mind spending the money, larger radar antenna has to be better. I'm not sure the 24 is actually more windage than the 24, which appears to be taller. Have to check the specs.

[rslifkin]

Windage and such is a concern with radar, but at the same time, radar lets you use the boat safely and effectively across a wider range of conditions. Some amount of performance sacrifice is acceptable for that in my mind.

[Dockhead]

Originally Posted by rslifkin

Windage and such is a concern with radar, but at the same time, radar lets you use the boat safely and effectively across a wider range of conditions. Some amount of performance sacrifice is acceptable for that in my mind.

Indeed. I've gotten to the point where I just don't feel comfortable sailing without radar no matter what the weather. My old set broke last year (turned out to be just the rubber band) and I was very unhappy for the couple of weeks I had to sail without it.


I would give up just about any and every electronic device on board, before I would give up radar. I would be quite OK sailing with just a depth sounder, radar, magnetic compass, hand bearing compass, if I had to.


And windage is not a large factor on a boat with a thick mast.

[tanglewood]

Thanks for the review.

To really test marpa, lock onto and track a target that is also transmitting AIS, and compare the two. AIS is what the target is actually doing, and MARPA is what the radar has reduced the target is doing. Presumably Simrad is up to par with others by now.


I haven’t looked at the geometry, but I wouldn’t expect a big difference between 18” and 24” in bearing discrimination. Move to a 6’ or 8’ open array and the. You will see a difference.

And a side question…. Who actually uses long ranges, other than perhaps for weather? I typically use 6nm or maybe 8nm on a passage, and 3 to 6nm otherwise. Plus a second radar on 1.5nm for close is stuff. I never use long ranges other than for curiosity from time to time.

[Dockhead]

Originally Posted by tanglewood

Thanks for the review.

To really test marpa, lock onto and track a target that is also transmitting AIS, and compare the two. AIS is what the target is actually doing, and MARPA is what the radar has reduced the target is doing. Presumably Simrad is up to par with others by now.

I haven’t looked at the geometry, but I wouldn’t expect a big difference between 18” and 24” in bearing discrimination. Move to a 6’ or 8’ open array and the. You will see a difference.

And a side question…. Who actually uses long ranges, other than perhaps for weather? I typically use 6nm or maybe 8nm on a passage, and 3 to 6nm otherwise. Plus a second radar on 1.5nm for close is stuff. I never use long ranges other than for curiosity from time to time.

Yes. tracking a target which is broadcasting AIS is exactly how I have always tested MARPA.


18" to 24" actually should make a big difference in bearing discrimination. It's a 33% increase in the baseline. But we'll see -- I haven't been able to see a big difference so far.



What concerns your "side question" -- long ranges, certainly anything more than 20 miles, are not needed for collision avoidance, nor will more range even be usable in most cases for ships because of the curvature of the earth.


Far more important than range beyond that is how well the radar works up close, and the lack of main bang and the extremely good DSP of the Navico CW radars are just brilliant for that.



You use the longer ranges principally for radar navigation and weather.


I've written it before, but I found the 4G radar to be very satisfactory for all my purposes (except only MARPA). The range was quite adequate -- you could see weather and land features out to 40 miles at least. I never felt myself wishing for more range.



And the close-in performance and the very high quality DSP of the 4G radar were just brilliant, making radar guard zones suddenly extremely effective.


Only noticeable downside to the 4G radar was the terrible MARPA. Not that big a deal for me since anyway I am used to doing traditional radar plotting. Even with sets with good MARPA I tend to just put the EBL on the target, which lets you see faster than MARPA can calculate anything whether you have a problem.


So if the HALO24 turns out to be no better than the 4G I won't be so disappointed. The 4G radar was one of the best pieces of electronics I've had on a boat in a lifetime of sailing. My hope is that it will be better for weather -- not just longer range, but better imaging of weather (CW is supposed to not be good at this). And even better bearing and target discrimination, even though I wouldn't say the 4G radar was disappointing in this regard.


We'll see. I've only had one short passage with the new set so far. I'll be leaving for a long cruise to Norway on Sunday and will gather more experience in the course of that.


Oh, and there are a couple of other supposed advantages of this radar:


1. Very high speed scan is available -- up to 120 RPM. I haven't played with this yet. I suppose this would be a big enhancement to MARPA performance, and will give you a better picture of target movement.


2. Specifically settable weather mode, bird mode, etc. I also haven't played with this. Should be interesting.