Water tank

Chief Galen Tyrol and his deck gang enter the water tanks after the explosion (TRS: "Water").

The water tank is the storage area aboard a Galactica type battlestar for water in fluid form, and is part of a greater water system that is capable of processing and reclaiming water for use with negligible loss. At maximum efficiency, the ship can go years without outside replenishment.

Water tanks aboard a Galactica type battlestar are located close to the hull, with at least six tanks on the port side at the head of the ship, just above the forward port landing bay. Two large flexible tubes connect to a system that allows underway replenishment of spacecraft from these tanks.

The internal structure of the water tank features a walkway for use during maintenance, after the tank is sufficiently emptied. Otherwise, the pressures inside the tank would kill a human, even if suited (TRS: "Water").

Galactica

Aboard Galactica, Sharon "Boomer" Valerii plants five G-4 explosives within the tank, detonating them to rupture both the inner and outer hulls, evacuating Galactica's water into space. After an investigation uncovers residue upon a honeycomb piece from the tank, it is determined by the Fleet's uppermost leadership that a Humanoid Cylon would have been responsible and that one such Cylon is aboard Galactica (TRS: "Water").

Later, Chief Galen Tyrol and Valerii make the mostly empty and repaired water tanks a location for their illict romantic rendezvous (TRS: "Litmus").

Notes

• According to Commander William Adama, Galactica-type battlestars have near unlimited capacity for water storage and reclamation. While some of its capacity may be purified drinking water, it may also have greywater facilities for cleaning and other usages not inclusive of human consumption.
• The water tank's location to the hull may also help with buffering against radiation, as water is used to as radiation shielding due to both its density and inexpensive nature.