Need for a marine radar detector??

[Higgler]

A co-worker mentioned that crossing the Santa Barbara channel in the fog last month that he came across a large tug pulling a 1000 foot barge with a large metal cable. His 19 foot Boston Whaler got within 50 feet of the tug, twas a bit scary. I was thinking of making an integrated antenna/radar detector for boats who might want a night time/ fog time radar detector. The detector would be small and you'd have to manually scan it to find the incoming radar. It would have some sensitivity adjustment too.

Questions;
Thoughts on whether this product would sell?

What frequency range of radars need to be included? 1.6-10 ghz? I realize some car detectors may pick up some of the signals, but not all.

Estimated price for such a product.

thanks,
kch

 

[MikeHalloran]

It might be a nice thing to have, but ...

It wouldn't have saved him from the barge.



Mike Halloran
Pembroke Pines, FL, USA

 

[colinp]

What you described is actually a pretty common piece of safety equipment.

http://www.survivalsafety.com/

It is called a Collision Avoidance Radar Detector. They sell for somewhere around $500.

In foggy conditions- exactly the conditions you would really want a radar warning receiver- a small boat might become invisible to marine radar due to temperature gradients. The same effect might reduce the range of the radar warning receiver.

Marine radars operate on X band and S band.
It might be a fun project.

-Colin

 

[Higgler]

colinp,
thanks for the link. $485 US price seems a bit steep for small boaters, although you only die once.
I envision a handheld unit manually controlled unit. I would think cost under $200 is expected.

Do you know of any other companies making this type product, I couldn't locate any in a quick search.

Thanks
kch

 

[colinp]

Hi Higgler,

I do not know of any other commercial radar warning receivers that operate on S band.

-Colin

 

[jsummerfield]

Check the marine catalogs. West Marine / Boat US, others sell these things. We buy cheap VHS radios for small boats, better radios for bigger boats. Bigger boats have radar. Some small boats owners buy radar detectors, especially those who do crossings, etc.

John

 

[unclesyd]

If you are going to run in open water or commercial shipping lanes the Collision Avoidance Radar Detector (CARD)is must and is very cheap insurance. Every boat that I venture out into the Gulf of Mexico now will have a least a working 5 mile radar and the CARD. If running in fog or at night keep the radio turned on the hailing channel. Another inexpensive piece of equipment that you can use is a Radar Reflector. This is metallic shape with right angles, newer ones make you really lite up, that will greatly improve your signature on someone’s radar screen even if your boat is equipped with a tuna tower or flying bridge. Back in the pretransistor days we wanted to be stealthy to keep our fishing spots secret, not anymore.
I don’t have the spec’s on the new 35 mile radar but the old one we had operated in the X-band. You also might want check with the radar detector makers about using a 360? detector on a boat. If you detect a signal start looking and talking.


Anecdotal:
Sea going tugs are not my biggest worry it’s the idiots in high speed boats of all sizes running wide open at night and low visibility conditions. I can’t guess the number of collisions in the last five years in my area of the Gulf. In the last 4 years we’ve had four large sport fishermen hit a sunken battleship (The Massachusetts) that has been laying on the west side of the local pass since 1/6/21, duly marked on all charts and located by a warning buoy. The old girl took the bottoms out of all of them. One captain asked while calling for assistance, “Who moved the Massachusetts”

 

[Higgler]

Thanks for the inputs.
I worked at Raytheon in Santa Barbara for many years. In the late 60's, three employees went into the Santa Barbara Channel at night for some RF testing and were never heard from again. I've been on that channel and it's damn scary in the fog, those huge ships are fast. Plus, I can't see them steering around a small boat. When you're in a channel, or call it a fiord, the radar returns are pretty cluttered from the islands at a distance of 3 miles. I don't know how well the ships radar can distinguish.


Any comments on;
Omni-directional detector vs. handheld narrower beam directional antenna vs. switchable omni/narrow beam.

As an antenna engineer, I can easily make a directional antenna very easily on printed circuit board, which will make for easy direction of arrival monitoring. I suppose I can also make an omni antenna on the same board and add a switch for direction finding, but that will limit sensitivity and hence range.

Thanks,
kch

 

[icrman]

In past flying days. I knew of an airport that had something called a DF steer. "Direction Finding" any way
I guess it was a sort of passive radar. The pilot keyed his mic and the radio acted like a transponder of sorts and a line on the CRT would go to the plane. They used a map overlay over the CRT to depict the land area. So how did this work?

 

[ssreese1500]

sounds like Unclesyd is from Pensacola!

Also remember this all you boaters, when a tug is under tow, she is supposed to be displaying an amber stern light in addition to the white stern light. If you see a tug with the amber light, be looking for something behind her, and keep in mind that there will be a wire in between the two. The weight of the wire will produce a cantenary, which means the wire will be under the water and you wont see it, but trust me....its there.

 

[Higgler]

The visibility was less then 100 feet when my friend encountered the tug. Not sure if the lights would have helped, but I'll inform him about the lights. That bit of info could save him the next time.

thanks,
kch

 

[dgallagher]

A simple radar reflector for less than $50.00 will tell the tug that something is out there - they will put off a pretty good signature. Won't help against a crazy speed boater, but will warn commercial traffic of your presence.

http://www.bluewatershipsstore.com/detail.aspx?ID=365

A sailor, I have a Raymarine Pathfinder, 2Kw, 24 NM radar integrated into my chartplotting GPS. I still have a reflector so the big guys can see me when I am not taking a peak.

 

[Higgler]

I believe there are minimum ranges that radar can see due to clutter. If you're moored in a harbor and start out when a large vessell is 1/2 mile away, they may never see you. Plus, would they know you compared to the large rock behind you. Maybe not.
I don't trust radar reflectors unless you are in open ocean.

Thanks for the inputs all.
kch

 

[berkshire]

Has anybody considered active transponders to improve the radar signature of a small boat. If so how many frequencys would need to be covered.
B.E.

 

[Higgler]

I researched active transponders awhile ago. There are a only a few out there.
You need frequencies in the 2.8 Ghz (commercial vessels) and 9.4 Ghz (private vessels) at a minimum.
The result you get in an active unit depends on gain of the amp between the antennas. They can do a bit better than a standard reflector, but the cost and cabling make it a bit less appealing than you'd think.

kch

 

[berkshire]

Well that not really the answer I wanted to hear. I guess I am going to have to stick to standard reflectors hung in the rigging.
B.E.