Is 2 kw enough for a radar unit

Maine Sail · May 16, 2013

RECESS said:
I have been doing some research into buying a radar unit for the boat. I have been reading that the 1.5 kw units are not very good at penetrating fog and rain. Also read a lot of comments that small fiberglass boats do not always get picked up until they are 3 miles or less depending on conditions.

What has been your experience with the minimum kw that is effective for 15 to 20 miles out? Penetrating fog, seeing upcoming weather, and night crossings is the main reason for purchasing

You can't really see targets 15 -20 miles out unless your target is very tall or your dome very high.. More kW usually means better target definition due to the narrower beam width but broadband has sort of re-defined this.. You can often see weather that far out though.

For example with a 20' dome height and a 12' tall target your radar can only see about 9.75 nautical miles..... Put it on a stern pole at 12' and have an 8' Sea Ray blasting at you at 40 knots and you can now see him at just 7.7 nm. Radar is all about line of sight...

Personally I think that Garmin still has the best "bang for the buck" at 2k or less for a radome and plotter...

CCHer · May 16, 2013

I had the Garmin 2kW and chartplotter combo on my previous boat. A decent price for the package as Maine says and it worked well. My new boat has the Simrad 3g which works very well also...maybe a few more bells and whistles than the Garmin which I haven't fully mastered. The big advantage though is that the Simrad has relatively small power consumption and almost immediate spin up; it uses a different technology from the rotating array which I don't fully understand (perhaps Maine can explain). It seems to see small near objects like oyster stakes better on short range and the long range is pretty much the same.

Gunni · May 16, 2013

How about 18 watts? Less power than your stern lamp. The Navico "broadband" radar. Turn it on, leave it on.

Jerry Clark H356 SV Persi · May 16, 2013

I have an older Raymarine Pathfinder 2kw and it is mast mounted and works fine. It is 10 years old and I am very satisfied. 4kw has somewhat better definition, but not too much difference. In the newer HD and broadband, I have no experience.

Bill Roosa · May 16, 2013

What do you need the radar to do for you?
sure a SpeedRay coming at you at 60 knots is scarey but it is not like you can do anything to avoid him. not trying to be funny here. Do you need it for navigating in the fog in areas where there are lots of above water obstructions that move around or for seeing weather after dark.....? I would think that a small fiberglass boat at 3 miles is not much to be concerned about. At 60 knots that is 3 minutes out. If it is low visibility and he is going 60 then he is a nut and there is no cure for that ailment. no matter what you do he is still a danger to himself and others. Radar will just inform you of that but you can't do anything with that info. I'm thinking ignorance is bliss in that situation.
What you need it for is kinda going to drive your choice.
To me it breaks down to do I need short range or max/horizon range. Not at all sure that has anything to do with the power of the radar though given some of the new tech.
In fog I just stay out of the shipping lanes and that seems to work as long as I keep a good look out for other folks doing the same. not too many folks even come out in the fog around here so radar is kinda useless as I'm well versed with the area.
Also, Bowditch has a great section on radar and reading the screen.

Ken Cross · May 17, 2013

Actually transmitter power helps, but so does a good receiver. Today's modern electronics pretty much remove the need for big power outputs of yesteryear. Even in the aviation world they have done away with big transmitters. You are interested in performance not how much energy can I send off into space. There have been several recent reviews (Practical Sailor comes to mind) that can help you make a good decision.

Ken

Ken