Radar Pole -- Radar Height

[a64pilot]

I can tell you my pole mounted 4G is not good for guard zones if there is decent sized waves, I get lots of returns, intermittent strobes, I assume due to the main beam striking the waves from the boat pitching and rolling as well as wave height, and antenna height.


Sent from my iPad Pro using Cruisers Sailing Forum

[a64pilot]

Radar will travel slightly over the horizon, I think about 1.2 times normal visual horizon.


Sent from my iPad Pro using Cruisers Sailing Forum

[Rorzech]

How long is it going to take a squall that's 32 NM away from you. If it's bearing down at you at 50 Kts , my best guess would be that you have at least a half an hour to reef some sails close some hatches & port holes. I move according to how fast I need to. In a pinch I could be squall ready in 5 minutes. Add 5 more minutes to that if I'm in the middle of cooking. I don't want to be woke up when the shipping container is a half mile away .A quarter mile is plenty of time for me to get my act together and steer around it. AIS is a really good tool to enhance ship detection. I believe we should carry as many collision avoidance systems as we can afford right down to simple radar reflectors and bright LED lights. I like to stand out like a Christmas tree when I can. Microwaves are not that healthy for us and having powerful radar systems kinda scare me a little like if a mounting bolt broke and pointed the unit right at my berth all night. I never say never. I like my smaller version digital G3 which IMHO is the best unit suited for people who share my views . I personally don't care what's farther than 15 NM away. I snap to attention the instant I open my eyes anyway. That's just me. So it just shows that there's room for small and large radars. It all comes down to personal preferences and we each have different preferences for certain. If I was so concerned I'd launch my AWACS GPS Digital Radar carrying Drone that can reach an altitude of 2 miles straight up and see everything within 450 NM 360 degrees around me. I can have it launched in 5 minutes and back on board in 15 minutes and know exactly what is any possible threat within 450 NM of my little boat. After a fast charge I can have it back up there in half an hour. <Just kidding but you can be sure there's a version in the works>

[Paul L]

Originally Posted by Rorzech

How long is it going to take a squall that's 32 NM away from you. If it's bearing down at you at 50 Kts , my best guess would be that you have at least a half an hour to reef some sails .........oa>

I've never used radar to decide to reef. I have often used it to determine the track of a squall and adjust by course, usually to avoid it. In light airs on a long passage I've used the squall track to get closer to the favored edge to get some sustained wind.

[BigAl.NZ]

Originally Posted by Dockhead

My AIS system works perfectly, so dealing with ship is a small part of what I use radar for. I use OpenCPN for complex collision avoidance with AIS. The only thing I would improve would be to go to a Class "A" system, which I will do in my next boat for sure.

I use radar for the following:

1. Enhancing visual watchkeeping at night and in bad viz.

2. Enhancing offshore watchkeeping with guard zones.

3. Navigation.

4. Collision avoidance with vessels not broadcasting AIS (mostly pleasure vessels, but fishing vessels at night are a real menace if you can't detect and avoid them).

5. Gauging distance to uncharted objects (other boats in an anchorage, etc.)

6. Detecting and gauging distance to channel markers, fishing pots, etc.

7. Keeping track of squalls and approaching weather events.


So the 4G radar excels at 1, 2 and 3 and is pretty good at 5 and 6.

It is somewhat usable for 3, 4 and 7, but lacks bearing discrimination to do 3 and 4 well. MARPA is almost completely useless.

A powerful open array radar would eliminate all the gaps.

I used a big Northstar open array on a 90' yacht I spent some time on a decade ago, and it was awesome. I wish I could have something like that on my boat, but I recognize this is probably a pipe dream.



For all its faults, the 4G radar does have one absolutely killer quality -- the signal processing is so good, that there are practically zero false alarms when using the guard zones. This makes them from something fairly useless on my old Pathfinder radar to a killer enhancement to watchkeeping, even in daylight, when offshore. This radar would be worth having alone for this quality.

Dockhead - did you end up putting this open array on a mast mount on the transom? pics?

[Dockhead]

Originally Posted by BigAl.NZ

Dockhead - did you end up putting this open array on a mast mount on the transom? pics?

No, I didn't. The comments in this thread convinced me that it was not a good idea (thanks to everyone who gave all that good advice).


I changed my compass last year to a Furuno sat compass, which has dramatically improved heading data on my network. This has improved the performance of the 4G radar more than I expected. Even MARPA sort of works now.


So I'm kind of resigned to it now. If I wanted to change the radar, I would have to change both of my plotters, which is a pretty big ticket project. If I did it, I would either go with the new generation Zeus plotters and the 24" HALO dome, or go all Furuno. Navico obsolete their stuff so quickly that I would be loathe to invest a lot of money into more of that gear, so probably I would lean towards Furuno.



But my first generation Zeus plotters are working OK, and the radar is adequate, so I don't have any burning ambition to do this soon.


What I really want to concentrate on now is getting good wind data. I'm replacing the wind instrument (again!) and I have a new DX900+ speed log, and an H5000 Hercules racing computer. Job 1 now is to get all these working right. I'm now splitting my time between my own boat, and my friend's Discovery 67 which we bought last fall, so I have less time to spend on my own boat. So I have to set priorities and concentrate on what is really important.