Multichannel seismic data from the "Bay of Plenty Neotectonics Whakatane Graben Extension" voyage (TAN9914) of the R/V Tangaroa. The voyage was undertaken as part of the "Extensional Back-arc Processes" project of the "Active Seabed Processes" FRST programme. The objectives of the programme are to determine the contemporaneous processes of extensional faulting, subsidence andc sedimentation in the Wanganui Bight and Bay of Plenty, to compare the mechanisims of extension, potential seismicity of offshore faluts, and the influence of sealevel cycles on sediment-tectonic interactions at opposite ends of the back-arc region of the Hikurangi subduction zone. Survey Leader: Geoffroy Lamrache Organisations: NIWA Seismic Instrument: 210 cu.in.,GI AIRGUN, 48 CHANNELS Navigation Instrument: GPS Ports: Wellington to Auckland