OCEAN is a tool for a posteriori visual data mining that uses the output of a text miner to help users better explore a document space. Clustered documents are transformed into a hierarchical 3D representation analog to Reconfigurable Disk Trees. An intermediary document representation allows for interface customization and offers a generic approach to 3D structuring of text miner outputs. An interactive exploration is offered that avoids tree manipulation and provides local 2 1/2D view of the disks. A user evaluation is reported that outlines the benefit of controlled document hierarchy traversal and 2 1/2D document layout.