New user to Radar questions

[Presentation]

I am very new to Radar and still learning.

I have not yet depended on it in fog or night. Instead I keep it on as we cruise and play with the settings, adjust the range, adjust the gain, compare what I see on the screen to what I see with my eyes, etc.

I don’t use the radar for navigation. My GPS Chartplotter does a great job of this.

My #1 goal is to avoid hitting a small unlit boat at night or in the fog or rain.

We seem to have some fishermen in small skiffs that don’t keep their light on at night. We don’t get fog often but do on occasion, so same would apply here.

Here are some questions.

#1) I’ve noticed some small items like a wave runner show up very well however a low profile jet boat may not even make a blip even with the gain at 100%. Am I doing anything wrong?

#2) What range to you normally keep your Radar at when in use for avoiding boat collisions?

#3) Do you keep “trails†on or off?

#4) Do you keep “rings†on of off?

#5) Is your confidence in the radar high enough to run at plane speed in the fog, beyond what you can avoid with eye sight alone?

#6) Any words of advice you’d like to share with a radar newbie?

 

[ImpulseIII]

Doug & Lisa,

In fog or at night I keep the range at 1 1/2 miles. I use the ring function. Never used the "trails".

Some small boats just don't show up. Radar is an aid to navigation, not something to rely 100% on.

When I can't see, I am not on plane regardless of conditions (fog, rain, night etc.). Just take your time getting to where you want to go, use the radar and GPS as adjuncts to your eyes, senses and "gut".

Fog sucks......... :smt101

 

[Asureyez]

Radar

Hi Presentation:

Radar on Asureyez is on from the time we leave our dock untill we tie up.

Except in close quarter ports and harbors I typically have my radar range set to 3 mile and range rings are always on.

Why 3 miles ... if I'm going 6 knots, I'm actually looking out 30 minutes run time and iIf I'm going 15 knts I'm looking out about 12-14 minutes of range and 7 minutes off my bow. If the chop off shore is steep and running say 3-5 feet, some small craft will be hardl to be seen because they are frequently bobbing below wave tops when the sweep hits their position. You'll only see these targets every 5 to 8 sweeps which makes them look like wave tops. In this situation I add in a little "Sea" and reduce the range to say 1.5 miles and set up "Wakes or for your radar Trails" which will allow repeated echos from the same relative position to begin to build a course profile and they will stand out from the wave tops as a few minutes pass.

When I'm further off shore in steep higher waves I have to add more adjustment.

If I'm running 20 knots, well off shore I'll move my range out to 6 miles to catch ship bridge tops that are just on or over the horizion.


Tips ... learn to use the MARPA features to be able to set your radar to track individual targets and provide you with possible collision data for course change conbsiderations.

Work with Varible Range and Varible Bearing markers smoothly as these features are really andy to get a soild compass bearing ona target many miles off your bow. Good for meeting other boats, or avoiding them as the case maybe. YOu can set danger spots in this manner and set alarms if your vessl approaches these marks too closely.

Sometimes when two radars are pinging each other and are both using high power, the echo will appear as a series of targets in a line away from the real target or multiple targets will be generated to cause you to think there is more than on ship out there. Dial the gain back to see if that is what you are seeing.

Sea Bouys, oil rigs, antennas and many other important markers will have a RACON installed on them. RACON's are electronic transmitters that send back to a sweeping antenna a strong microwave burst that will appear as a disproportionate sized echo soemthing like and exclamation mark which dominates the area of the sceen. You can't tune out this signal and you are ment to see it big time and react according to the nature of the mark it is on. You will see RACONs noted on paper charts, electronic charts might require a "roll over" to see this character noted.

When using radar and chartplotters at night really dial back the brilliance as this screens are very bright and can blow away your night vision. My Raymarine unit is so bright even when dialed back it causes me difficulty so I keep it covered by a thin dish towel from the galley and peek under it for a quick peek without staring at it more than a few seconds.

The range settings over 12 miles are generally useful for seeing storm clouds and rain storm direction.

I'm confident of my radar and how to use and and yes, I let it be my eyes where I can't see but I don't over run my ability to react to what I'm seeing and being told. If all I have to go on is radar, I'm slo-mo on the throttles.

 

[Petep]

we run ours at 3/4 mile or 1 1/2 most all the time.
Asureyez did a great job with his summary, Practice as often as you can and read the manual, you will get it! The only thing I would add is that please remember to turn off the radome/array when you enter into a harbor, as I don't like those radars spinning in the harbors right next to me...I call it "popping the corn". I also don't like to keep my rings on - I use to run with them on years ago, my 40something eyes are not what they use to be.
we also don't leave our "wakes" on. It seems the only time we use a very large scan setting is when we are way out and want to see freighters or something in the lake to see if anything is out there.

 

[goblue]

Yep. Small boats show up and disappear depending on roll, pitch and yaw of your boat and the target.

When I cruise, I'm generally on 6 miles until I pick up multiple targets near and inlet, usually fishermen. As I get closer, I drop down to 3 miles and even a mile and a half if visibility is poor. When I'm within 12 miles of a prominent landmark I sometimes turn off the chart plotter and pick up a geographic point and lock onto that with the auto pilot. When coming into a harbor 6 miles out I'll lock onto the lighthouse and use the autopilot and reduce range according to conditions such as traffic and visibility. Sometimes I switch to 72, 48 and 24 miles when cruising to look at the tops of thunderheads.

Almost always use the rings.

Use the overlay feature a lot of the times and sometimes I split the screen and add data boxes.

The auto gain on my Raymarine works well so I usually let it do its thing without going manual.

I use the trails because it's nice to see the direction of targets on open water.

Brilliance on my radar works well and can be turned down to almost nothing which works well at night.

We go slowly in fog and do not run on plane. We run at a speed that allows us to stop the boat should something come out of the blue....sort of like outdriving your headlights in your car. You don't want to do that.

This is definitely a tool we use all of the time. Learning to use it in clear weather is a good learning approach.

 

[ylwjacket]

The only thing I would add is that please remember to turn off the radome/array when you enter into a harbor, as I don't like those radars spinning in the harbors right next to me...I call it "popping the corn".

Why is that?

I turn mine on at the dock, and turn it off at the dock. I've never really thought about it bothering anyone in between, and I've never heard anyone bring that up before.

Just curious.

 

[goblue]

Some people believe that you subject them to lots of radiation by watching storms at the dock with radar or otherwise running it in a harbor. The acutal amount is virtually insignificant due to the pulsing and band width of the signal, but this is what people worry about.

 

[DS410]

Mythbusters did a piece on that - tried to cook a turkey or chicken or something. Tied it to the radar array on a military vessel and turned it on. After an hour, the internal temp of the bird actually decreased from being out in the wind for so long. Myth - BUSTED.

As for radar use, I usually keep it in close for better resolution. 3/4 - 1 1/2 miles will generally provide you with plenty of room to avoid a collision, especially if you are in conditions where you really need to be using the radar, like in fog or at night - most folks will be going slower anyway.

That having been said, the one time I really needed radar was at night, northbound on the Chesapeake Bay. It had rained earlier but was clearing as it got darker out. Not much traffic at all. We were on plane at 18 knts, (in our previous 370 Dancer), and used the radar mostly to see the channel markers (and avoid hitting them). If you ever need to do this, DO NOT NAVIGATE BY CHARTPLOTTER to avoid hitting charted objects!!!!!!!!!!! Use the chartplotter only to stay on course, BUT if you see a blip on the radar, assume it's solid and don't let it pass through the center of the radar screen :smt018 - cuz that's you. :grin:

Also, go ahead and use the rings if you can - it gives you a more precise measure of your distance to an object or land mass. You can actually navigate this way if all else fails by putting the shoreline on a range ring and keeping it there as you track the coastline. You can probably also set a range alarm to warn you if the coastline gets too close to your vessel.

Finally, take a course or get a video or something. It's amazing what you can do with radar. Good luck.

David

 

[CJ Martin]

Mythbusters did a piece on that - tried to cook a turkey or chicken or something. Tied it to the radar array on a military vessel and turned it on. After an hour, the internal temp of the bird actually decreased from being out in the wind for so long. Myth - BUSTED.

Hope this isn't too much of a derail, but take what you see on that show with a grain of salt. As a former Navy radar tech, I am here to tell you a modern high power fighter radar WILL ruin your whole day if you got caught in the main beam with the safety interlocks overidden. Smaller A/G and navigation radars don't put out that kind of power, which is likely what they "tested".

Another one I saw them "bust" was the one about someone getting cut in half by a parted arresting gear wire. Unfortunately, I have seen otherwise (not first hand thank goodness, but I've seen several PLAT videos that are pretty grim - sounds morbid but it makes for good training). The test they ran for that was so far off reality they might as well have not done it.

To get back on track, you shouldn't radiate even a low powered boat radar when people are nearby and at the same level as the array - for example, at the dock at low tide. The effects of low level RF radiation are not well understood, but in my experience deserve respect.

-CJ