Whats this called?

[Donside]

This was on the rail of my boat when I bought her, it’s stainless and 5 inches by 10 inches.
No clue as to what its for but I want to get rid of it.

 

[Sticky Fingers]

Fender basket? For a very small fender.

 

[dunedin]

MOB throwing rope holder?

 

[RunAgroundHard]

MOB throwing rope holder?

Yes

Seago MOB Rescue Throw Line Kit - Marine Scene

 

[Sticky Fingers]

Or for a throwing line?

 

[Sticky Fingers]

Oops too slow

 

[Boathook]

So possibly, somewhere on board is the throwing line.

 

[Donside]

Thanks,
now, can I give it away?

 

[lustyd]

It's a Magnum holder so you don't spill the bubbly on passage