We present a transient model for an electrically segmented polymer electrolyte membrane (PEM) fuel cell which is run until extinction from a finite oxygen supply. The experimental cell is divided into 16 electrically isolated pucks which are fed oxygen from a small reserve and hydrogen from a conventional flow field. The experimental voltage and through-plane current in each puck, and puck-to-puck currents are recorded and compared to computed profiles. Seven qualitative characteristics of the current profiles during discharge are identified. These are used as targets for parameter tuning, from which puck-to-puck water distribution within the membrane electrode assembly (MEA) is inferred. The model is sensitive to system parameters, and holds promise as an in situ diagnostic tool for tracking this distribution by using MEA oxygen transport characteristics.