What is this? Help needed identifying rig object

[Seafarer7]

It looks like a 1”+ diameter PVC tube, over a foot long, attached to the aft shroud of a 39-foot sailboat with 4 stainless steel eye loops in a way that allows it have free up-down motion as well as rotation around the shroud. The top end is capped.

Any ideas what this might be?

[Sailmonkey]

Aft shroud meaning backstay?

I’ll wager it’s to contain the flag end of a MOB pole

[captain465]

It is a protective covering for the single sideband radio. Sideband radio can put out a substantial energy that can be harmful and dangerous. The backstay is being used as an antenna.

[Sailmonkey]

Originally Posted by captain465

It is a protective covering for the single sideband radio. Sideband radio can put out a substantial energy that can be harmful and dangerous. The backstay is being used as an antenna.

Protecting what from what?

[Marathon1150]

Originally Posted by Sailmonkey

Aft shroud meaning backstay?

I’ll wager it’s to contain the flag end of a MOB pole

This is my guess too - MOB pole flag protector. And it would keep the pole from flopping around (depending on how it is attached to the boat to allow for quick deployment).

[boatman61]

It's more likely a modern one of these..

[boatman61]

Opps.. Forgot to say... Its a Radar reflector..

[Seafarer7]

Thanks!!! Makes sense as a MOB pole holder. There is no SSB onboard and the backstay doesn’t have insulators typically of an SSB antenna.

[stormalong]

Originally Posted by captain465

It is a protective covering for the single sideband radio. Sideband radio can put out a substantial energy that can be harmful and dangerous. The backstay is being used as an antenna.

Not likely - no insulator or wire attached below it. I vote MOB flag cover.

[Seafarer7]

Originally Posted by boatman61

Opps.. Forgot to say... Its a Radar reflector..

Yours is quite a compact reflector. Mine is just an empty capped tube, in all likelihood just an MOB pole holder left over from a PO.

Now I know what it is, I’ll likely be removing it, as it throws some shading over my new 1,335-watt solar install.

[boatman61]

Originally Posted by Seafarer7

Yours is quite a compact reflector. Mine is just an empty capped tube, in all likelihood just an MOB pole holder left over from a PO.

Now I know what it is, I’ll likely be removing it, as it throws some shading over my new 1,335-watt solar install.

Ahh.. Missed where you said it was empty..

[psk125]

Originally Posted by boatman61

Opps.. Forgot to say... Its a Radar reflector..

Based on the tests of the shroud-mounted tube radar reflectors, it would have to be that big to be at all effective. It would have to be stuffed with bunched up aluminum foil too, and would need a bottom plate to keep it all in. MOB pole cover seems the only sensible option.

[dfelsent]

If the boat was raced it could be a holder for a protest flag.

From another web site
“
.......
The flag remains rolled inside the PVC tube, both hidden from view and protected from the elements. If (hopefully not when) the flag is to be depolyed, simply slide the PVC tube upwards along the backstay while the flag and cord remain in place, and the flag will unroll for display.
.........
“

[boatman61]

Originally Posted by psk125

Based on the tests of the shroud-mounted tube radar reflectors, it would have to be that big to be at all effective. It would have to be stuffed with bunched up aluminum foil too, and would need a bottom plate to keep it all in. MOB pole cover seems the only sensible option.

True.. and mounted higher which is why on my boats I fit two, one above each of the spreaders. The hanging ones are fine for day sailing but on multi day trips in all weather's rehanging due to chafe gets old quick.
But I promise a more forensic examination of the evidence next time..

[bluewaterbill]

Looks like a home-made holder for a man-overboard pole. Should be a “cup-style” holder at/near deck for the bottom of pole. If you plan to use a self-contained MOM8 unit or similar, you won’t need the PVC tube.