To reflect or not to reflect

[Bycrick]

I’m not sure what you mean. The "standard" target for measuring radar reflections is a smooth sphere of a specified size. It’s easy to measure but not a particularly good reflector in the real world because most of the reflected energy isn’t returned directly to the transmitter. If by "disco ball" you mean a ball covered with small flat pieces of metal, it would have a smaller radar cross section (based on the size of the tiles more than on the total size) and greater differences between the peaks and valleys of the returned signal strength.

[Differentroads]

An effective radar reflector is a must. But it has to be effective.
I hang one of those Plastimo tube type reflectors in my rigging more for compliance than the expectation that it will be picked up by a ship's radar with enough reliability to trigger their alarms. For that I have a See Me active radar enhancer. I'm told that it doesn't make my 10m sailing cruiser look bigger, as people seem to think. It gives a clear and consistant ping on their radar screens from a much longer distance than a passive reflector. And when I call up ships on the VHF to check CPA and their intentions they confirm they have me on radar and have been seeing me for miles previously.
A question for merchant mariners out there. My radar enhancer works only on x band. The newer model works on x and s bands. What difference would that make for a small vessel's visibility on a ship's radar?

[a64pilot]

This is one of those should I answer questions.
X band gives better resolution but is range restricted, if you have ever played with a fish finder it’s the 200Hz setting, good resolution but won’t work in deep water.
The S band gives much greater range but not so good at resolution. Fish finder it’s the 50 Hz setting.

The S band being a much lower frequency requires quite a large antenna and due to its lower frequency and for the same reason it can’t see small targets very well, that makes it not as likely to suffer signal degradation from rain or snow etc.
Now I’ve never been on the bridge of a ship except as a visitor.
http://officialseapeeps.com/the-x-ba...he-difference/

My question is surely they would run both? It’s not a one or the other?

A transponder won’t make you appear to be larger, but it definitely will appear that your RCS is much larger, it’s not really a return, your broadcasting a signal.

It’s literally the difference is scanning with a searchlight, a Radar reflector is reflective tape, and active transponder is the other boat shining a light back at you.
One you see a little reflection, the other a bright light, not a big as in size light, but certainly a bright one.