Radar on E27

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chrism

Inactive Member
From what I read, you really should have no problem having radar onboard if you keep an eye on what's happening around you. Learn how to use it in daylight, so at night and in the fog, you will know how to use it. Just because it's a law doesn't mean it makes sense, and I can almost guarentee you that most of the boaters in my harbor don't keep radar on constantly.

If you do colide with another vessel, you were either not paying attention to the road, or you didn't know how to use your radar, because you should be able to see a boat coming during fogless daylight.

Radar is a great tool, and I used it on a charter up in foggy Maine this summer, and it was a valuable tool. I used it in an unfamiliar channel, picking out boats and bouys ahead. If you have one, learn how to use it, because if you do colide in the fog with your radar off, you deserve the blame.

Chris
 
Jeff Asbury

Jeff Asbury

Principal Partner
Thanks for checking out the old photos.

Len,

Thanks for checking out the old photos. I posted those about a year ago. Here's my stock answer to your question about the efficiency of the radar while heeling. In my experience there usually is not much wind if it is foggy. There for I am not heeling while I am under power. At least that seems to be the way it is out here on the west coast such as the San Pedro and Santa Barbara channels. If I were sailing in the fog I would certainly be able to control the heel by letting my sails out or reefing. I agree with Chris that you should learn how to read the thing in fair conditions. I actually purchased a book and a video on how to understand what I am looking at. The Coast Guard also has classes I believe.

Skipper Jeff, Out :egrin:
 
S

scourge

Member II
Radar - Photos

Loren, Jeff,
I would assume that most of the use of the radar will be under power, ie, fog
conditions, which I have been caught in a couple of times, and was under power, but I am planning a little longer cruise on Lake Michigan this summer and plan on (if the wind is right) sailing through the night, which then the boat may be heeled somewhat.
I will have to take a look at the Garhauer Stern Post. I didn't know that
they made them. It is adjustable? That would certainly be an option. Even going with a fixed stern post would not be that bad, but I was/am trying to find the optimal solution. I have seen some links to a 'Waltz self-leving radar mount' but I believe the company is out of business now and the links are old, hence why I was looking for even a used mount.
I had asked on the Sailnet thread about mounting a pedestal guard. I thought at one point, I saw somewhere some pictures of someone who installed a pedestal guard on an Ericson with the split cockpit. Sound familiar
to anyone

Len
 
O

oceandreams89

Member II
I installed a 2kw Raymarine dome on my boats mast a few years back. It is about 22-24 feet off the deck and works fine when heeling. There is some degradation in resolution with very steep heeling angles but we try to limit our heel to 12-18 degrees anyway when cruising. The radar detects targets which are obviously taller than flat on the water so a slight heeling angle will still pick up targets which are taller than the water surface. Smaller targets could potentially be missed when approaching your high side at close range. The cost of a articulating antenna mount did not seem to merit its need to me thought, since as has been said before, when you really need the radar in fog, it most likely is not windy and you are motoring. The mast mount in my opinion looks cleaner as well, and only a handfull of times in light conditions have I had to go forward to clear the genoa from the antenna while gybing. (it also is a very large genoa)

The other thing to consider is your actual transmit range. A mast mount will pick up targets further away because the radar horizon is further out when mounted higher. (about 6-7 miles for flat targets with a 23 foot antenna) If you have the radar on a stern pole your radar horizon is about 4.5 miles. To calculate this take your antenna height's squre root and multiply by 1.44 for approximate radar horizon. (23' S.R. = 4.795 X 1.44 = 6.91 miles) In addition you can take the target height lets say for a barge about 20' for example. (20 S.R. = 4.47 X 1.44 = 6.43 miles. Add that to your radar horizon of 6.91 miles and you should detect the barge at 13.3 miles out. So purchasing a big 48 mile radar is a waste for range information. The only thing you will pick up at 48 miles are thunderstorms. (target descrimination is better though with a higher power transmitter.)

Battery draw is another issue to consider. A 2kw antenna will draw 2.5 amps/hour of battery without the display, and .75 amps on standby. Considering the length of your voyage a sailboat needs to consider this draw based on the operational needs of radar use in your prevailing sailing conditions. The CG regs say you must keep a propper lookout. This means the mandatory use of your radar, in my opinion, when conditions prohibit the abaility to see and avoid visually, or at night. If you have the power resources to run it continuously in daylight with unlimited visability and while sailing then thats great. However, the need to manage your boats power for when it is needed should also be considered. It would be no fun to have run your radar transmitter all throughout a beautiful day on the water only to find the wind die and the batteries dead for engine start, or in an emergency. I run the radar continuously when motoring anytime, in the rain/haze/fog, and at night, and use my judgement of conditions and traffic situations at other times. Most of these modern units you also can program to scan at set intervals. You also can set them for a specific number of scans before returning to standby, minimizing your power consumption, and the units can also be programed to give an audible alarm if a target penetrates your scan range.

Also, it is useless if you can't see the screen. Many people mount the displays in the companionway or at the helm in a pod. I did the later and it works great. Having it below at a chart table is ok if you have someone who wants to sit below and watch it all the time and yell up steering corrections if needed, but the ability to instantly look at and interpret the screen at the helm is invaluable, especially when traffic is high. Also there are so many buttons to push on these things that it is nice to have the display at your fingertips to change between radar / chart data in an instant. The only drawback to the display being directly in front of you is at night. While the latest displays dim significantly, and have a night screen mode, the light in front of my face is annoying at night. I usually place a towl or washcloth over it and peek under every few minutes just to get rid of the excess light. I like just the red glow of a compass light at night.

Anyway, I hope some of this rambling will help.

Just my $0.02

Todd
 
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