Looking at the drawings of the sailboat in question, it looks like it may
have a swing keel.
I cropped and enlarged the bottom section of the drawing he

http://www.eisboch.com/keel.jpg

I read up on swing keels on large yachts and they typically are retracted
with either cables or hydraulics.
The barrel appears to be located right over the aft section of the swing
keel (if that's what it is) and the "pipes" that appear to go from the
bottom of the barrel into the yacht interior might be cable guides.

So, maybe it houses a winch for retracting the keel?

I have not received a reply yet from the broker company.


The original picture of the deck "barrel" is he

http://www.eisboch.com/barrel.jpg

Eisboch