Mobri Radar Reflectors

[bbowman294]

We have a new (to us) IP350 and purchased two Mobri radar reflectors. What are your suggestions on mounting - mast, stays/shrouds or.................

Any pictures???

Thanks, in advance,

Bill

[Steadman Uhlich]

This is not the answer you want, but I feel a moral obligation to share the following with you. What follows is written in a friendly tone of voice, with the sole intent to help you.

I would not mount them. I would return them. I would buy another, much better performing type of reflector.

Short answer: Based on reputable, professional, laboratory and field, independent testing (by others), I would NOT use that type of RADAR reflector. That is my opinion, based on reading the test results.

Here is what I suggest:

Have you read the following independent tests of RADAR reflectors?
http://www.ussailing.org/wp-content/...tor%20Test.pdf

Particularly Summary pages 30 and 31?

Why?
Because the type of reflector you purchased was "not suitable" (ineffective, with rapidly decreasing effectiveness if the boat is heeled even as little as 1 degree).

Excerpts:

" The 4” tube reflector performed very poorly."
" The 4” tube reflector is not considered suitable due to its poor performance. It is also recommended that the 2” tube reflector is not suitable since the performance of this target will be even lower.

" It is recommended that poorly performing radar reflectors are not fitted as it is possible that the user could be lulled into a false sense of security believing that their chances of detection has been enhanced."

"The 4” Tube reflector had a good peak RCS of 9.3m2 at 0 ̊. However, as the elevation angle increased the RCS rapidly decreased. Even at 1 ̊ the stated performance level had dropped to 0.12m2.

The MOBRI is a brand name, and the brand name may differ (e.g. Plastimo) in different locations due to distribution channels. It is the 4" tube reflector that was tested.
_____

Also read the following article which tested the common types.
http://keyassets.timeincuk.net/inspi...ce_ym_june.pdf

In this article, you will see the MOBRI tube type reflector was NOT recommended, because of poor performance when a boat is heeled, on the water very poor performance, etc.

[svHyLyte]

Originally Posted by bbowman294

We have a new (to us) IP350 and purchased two Mobri radar reflectors. What are your suggestions on mounting - mast, stays/shrouds or.................

Any pictures???

Thanks, in advance,

Bill

Bill,

We have two of the reflectors that are mounted in our rigging, above the upper spreaders, on the mast side of the uppers such that they are angled inward with the wire, but one or the other is generally vertical with the heel of the yacht when under way. Ours are mounted with several wraps of .042 annealed 302-304 seizing wire, available from Defender.com reasonably inexpensively. While some claim these are not particularly good reflectors, it has been our experience when speaking with other yachts, fishing boats and commercial ships equipped with radar, both day and night, that we appear as a pretty clear target on their scopes at the correct range and bearing. Perhaps coincidence/perhaps not. However, not long ago we had occasion to speak with the master of the Key West Express out of Ft. Myers Beach early one evening when he hove into view from behind us and inquired as to our visibility on his scope. He responded that he'd had us for "the last 10-12 miles" and, as we were moving so slowly (by his 30Knt cruise standards though we were making 7 kns at the time) he's ascertained that we were a "blow boat" before picking us up visually.

FWIW...

[Paul L]

Originally Posted by svHyLyte

Bill,

We have two of the reflectors that are mounted in our rigging, above the upper spreaders, on the mast side of the uppers such that they are angled inward with the wire, but one or the other is generally vertical with the heel of the yacht when under way. Ours are mounted with several wraps of .042 annealed 302-304 seizing wire, available from Defender.com reasonably inexpensively. While some claim these are not particularly good reflectors, it has been our experience when speaking with other yachts, fishing boats and commercial ships equipped with radar, both day and night, that we appear as a pretty clear target on their scopes at the correct range and bearing. Perhaps coincidence/perhaps not. However, not long ago we had occasion to speak with the master of the Key West Express out of Ft. Myers Beach early one evening when he hove into view from behind us and inquired as to our visibility on his scope. He responded that he'd had us for "the last 10-12 miles" and, as we were moving so slowly (by his 30Knt cruise standards though we were making 7 kns at the time) he's ascertained that we were a "blow boat" before picking us up visually.

FWIW...

The interesting question is what would your boat's radar signature look like without the two reflectors. Not all sailboats make poor targets.

[svHyLyte]

Originally Posted by Paul L

The interesting question is what would your boat's radar signature look like without the two reflectors. Not all sailboats make poor targets.

That Paul, is a good question but one I do not intend to explore for he moment. As and when our reflectors give up the ghost, and they will as the plastic enclosure tubes invariably fail due to UV, we may go with a different, reportedly better type/style so long as it/they can be similarly mounted so not to interfere with our spinnakers/sails. And, during any interlude between old and new I will see what others say as to our "signature" and report back (assuming, of course, our reflectors give up the ghost before I do!) Until then, I'm happy to be seen/have a signature at all, eh?

[Bluemansailor]

I have a mobri mounted just above my spreader. Hetrs my story of why i think their great.
I was about 200 miles off the coast of Portugal heading towards Porto. I saw a rather large sailboat sailong towards me. Im 32' i guess him at 70-80.
He came within a 100 feet of me and i asked all ok?
He replied" i wanted to see how big you are since you have a large radar presence" i said thanks ... End of first hand experience!!!!!!