Resurrection tub

Sharon Valerii is reborn in a Cylon rebirthing tank.

A Cylon rebirthing tank is a large tub where the consciousness of a deceased Cylon agent is transferred to a new Cylon body that is suspended within a thick gel. A blue light shines down onto the resurrected agent's head.

The tub apparently acts as a receiver from a Cylon download station (either planetary-based or via a Resurrection Ship) where the consciousness of a killed Cylon agent is re-integrated into a new body to begin life anew. Other agents tend to the new body as its consciousness reforms, encouraging and comforting the recovered agent in a fashion that may be reminiscent to viewers as midwifery.

The copy of Number Six that plays a dominant role in the Fall of the Twelve Colonies is resurrected in the tank, as is the Galactica-stationed Number Eight model formerly known as Sharon "Boomer" Valerii (Downloaded).

The rebirthing tank plays a principle role in boxing Cylons as well. The Cylon to be boxed is killed and allowed to resurrect within the tank and just like the resurrection process, another Cylon is there to to receive them. Instead of helping them to adjust to their new body, the Cylon present informs the revived Cylon that they are going to be boxed then removes a small data storage device from the side of the tank which contains the consciousness of the Cylon to be boxed. With the device removed, the Cylon in the tank becomes lifeless. Apparently, a newly downloaded Cylon cannot physically resist, aiding in the process (Rapture).