What is this blue coral called?

[Shipwreckscanada]

I don't know if this is the right place for this question but here it is.

I went diving in Roatan Honduras last week. I took some photos of this blue coral and no one there is able to tell me what they are called. Does anyone know?

I was lucky to get an eel in this shot.

 

[CuzzA]

Not a coral, looks like an oddly shaped azure vase sponge.

Nice photo btw, quite the collection of diverse life on that rock.

 

[Wookie]

Not a coral, looks like an oddly shaped azure vase sponge.

Nice photo btw, quite the collection of diverse life on that rock.

+1, if you need a second opinion.

 

[diversteve]

or 1/2 of one...

 

[KeithG]

Azure vase sponge, but normally they point upwards.