What type of Radar is best?

[travlineasy]

During the next few months I'll be setting up the electronics on my newly purchased Morgan 33 Out Island. The GPS/Plotter I've selected is a Lowrance HDS-7, which has an incredibly bright display, even in direct sunlight. There are a huge number of options to select from, including a split screen showing the GPS chart and fish finder, plus a radar overlay of the GPS chart.

I've looked at two Radar systems, Garmin and Lowrance, both of which appear to have direct connection to the HDS-7 via an Ethernet connection on the back of the unit.

The Lowrance is BR-24 is a broadband radar unit. It only draws 17-watts, which is about half what the Garmin draws. And, it claims to have better close up signal resolution and higher definition. Plus no radiation.

The Garmin GMR-18 draws about 33.5-watts, 32-mile range, which is the same as Lowrance. It uses X-band, digital radar, which I assume does give off some radiation, but I'm not sure.

The Lowrance unit weighs just over 16-pounds, and there is no mention of mounting hardware, brackets or cables. The Garmin weighs slightly less at just over 15-pounds.

First and foremost, what is the difference between Digital and Broadband radar systems when it comes to overall performance and ability to see smaller targets?

Next, I assume the best location for mounting the radar/radome is on the mast. One article I read said 18 to 22 feet above the water seems to work best and eliminate much of the sea clutter. Does anyone know what would be the ultimate height?

Finally, I've recently seen swiveling radar antenna mounts that keep the antenna level at all times. Looks like an ingenious idea that would solve a lot of close range reception problems encountered in rough seas. Does anyone have any experience with this self-leveling antenna mount?

Thanks in advance,

Gary

[erps]

I just installed a GMR-18HD on our boat. There were warnings about having crew too close to the transmitter/receiver, so I guess that's evidence that it puts out some radiation. Can't help you out with the rest of your questions.

First and foremost, what is the difference between Digital and Broadband radar systems when it comes to overall performance and ability to see smaller targets?

Although I don't have direct knowledge of a side by side comparison, on our first trip out with the new Garmin Radar, we picked up a duck that flew by the boat. When I realized what I was seeing moving across the screen, I watched the duck and it's blip on the screen and I figure the radar tracked it out about 200-300 yards beyond the boat. The weather conditions were no rain and calm water, so the set was tuned up with a lot of gain.

[Maine Sail]

Garmin works with Garmin and Lowrance with Lowrance. Unless things recently changed these domes are not N2k they work on specific brand protocols.

As for self leveling. I owned a Questus and it is a very nicely engineered piece of equipment to solve a problem that is not a problem. I did not and would not waste a penny on it again.

I always prefer a mast mounted dome for performance. Every boat I have had with a stern pole, including our current boat, had poorer performance compared to a mast mount, especially in rough seas. If your sailing in a bay then a pole can work. Mine will eventually go on the spar, possibly even this spring as I hate the pole that much..

[haffiman37]

The location where to put the dome might depend on a lot of factors:
The higher you get it, the longer effective range.
However the higher up, the more 'movement' and distortion in heavy seas.
On my SO 37, I decided to gimbal-mount it at a stern pole.
Works perfect up to about 4 miles (surface echo), which is the most interesting range.
It does not get tangled into my 140% genua or spinaker.
If for some reason I loose my mast, I still keep it working!
It is, if needed, easy to service compared to one up in the mast, and you have no risk of damage due to 'flowing current' in your mast.
If possible, avoid mixing different brands in a set-up like you mention. If anything goes wrong, be sure the supplier will blame the other 'component' of which he has no responsibility. It may be the same dealer selling both brands, but you may not always be at his place if anything goes wrong!

Remember Murphy's Law!!!

[Hydroplane]

Good points!
I have always used radar as a collision avoidence tool and relied on GPS, chart plotter, compass, etc. for navigation. I've heard too many horror stories about collisions when the radar was tuned for long distant targeting.
I am new to sailing though and will eventually install radar on my boat. Really enjoy reading these types of threads, hearing different perspectives.

[haffiman37]

The best 'use' I in fact had from my radar on my trip across Atlantic and Pacific was when entering anchorages at night.
Nuku Hiva (Marquesas) with 100+ boats at anchor and the most without lights, is not easy to get into at night. Getting safe distances when dropping the hook is next to impossible without radar, and you need to go down to less than 1/2 mile range!
As collision warning in places like the British Channel or Singapore for that sake, priceless at night, but due to number of echoes you will probably prefer to concentrate on the ones 2-4 miles out. An 8" screen with 200 echoes gets rather messy!
The max range came in use from time to time, but only out in the middle where no others were passing by. Used it to track squalls and thunder to if possible either avoid or getting some wind.
Setting up the radar and reading it correctly demands a bit more skill than what most vendors admits. They are not just a 'plug and play' sort of thing'.
You have to learn its limits and hopefully not the hard way.

[Yorksailor]

Mine is a 48 mile 4kw radar mounted 25 ft up the mast on a fixed mount. We pick up big ships at 30+ miles which gives us lots of time to track them and small fishing and sail boats at 5-6 miles.

The company that installed it said a gimballed mount was not necessary when mounted high on the mast and that has proven to be true.

I also agree with Haffiman, it has proven invaluable in crowded anchorages, on moonless nights, when half the boats are unlit.

The position can be seen on my avitar

Phil

[Maine Sail]

Originally Posted by Yorksailor

Mine is a 48 mile 4kw radar mounted 25 ft up the mast on a fixed mount. We pick up big ships at 30+ miles which gives us lots of time to track them and small fishing and sail boats at 5-6 miles.

Phil

Where does one get one of these magic radars they defy conventional radar ranges...?

In order to "pick up" big ships with a 25 high dome they'd need to be really, really big as in 390 feet tall! Have not seen many 390' tall ships. Even the USCG Eagle is only 295' to the very top of the spars, a 100' less than you'd need to see it at 30 miles. Even active reflectors like the Active-X can barely hit 30nm. Without electronic aids you can't physically see 30nm with a 25' high radar. I'm all ears though..

Furuno Radar Range Calculator

[chef2sail]

Unless you are an air traffic controller ( for boats )or meteorologist (tracking T storms), most of my use of our radar is done within the 5 mile range. While the extra 15 feet it would be up the mast as oppposed to the pole would pick some small ducks...wood up better, Oours is adept at identifying everything we have every needed it to do at the closer range (5 miles). If we did more cruising in large shipping lanes I might feel different

Placing it on a stern pole has the advantages which were mentioned above and the disadvantage is its range. I like the ability to fix it easily as well. Our pole also serves as the TV antennae mount, chartplotter, antennae mount and the dingy engine hoist.

Stay w

[travlineasy]

Thanks for the replies everyone--lots of good information to absorb over the next few weeks.

Gary