This dataset contains geoscientific data logged during PACMANUS 4 (FR09/97) on RV Franklin 8.10-3.11.1997 in Manus Basin, Papua New Guinea. These data include logged station coordinates and information for sediment grabs and cores, CTD/hydrocast operations and samples, camera/video tows and footage, bathymetric surveys and geological and fauna samples. The principal aims of PACMANUS IV (FR09/97) were to conduct further studies of seafloor hydrothermal activity at the PACMANUS and SuSu Knolls sites defined by cruises FR-08/91,FR-05/93 and FR-10/96 in the eastern Manus Basin, Bismarck Sea, and to test other volcanic edifices in the vicinity for hydrothermal activity. With only about 8 hours lost through equipment malfunction, during 12 days 10 hours on station we conducted 36 dredges, 18 grabs, 10 sediment cores, 14 hydrocasts and tow-yos, 15 camera-video tows, and 4 deployments of a vent fluid sampler. Twelve echosounder profiles with specific geological objectives were collected, partly during transit, and 59 operations plans involving 272 way-points were issued. A total of 207 km of cable was hauled, and a distance of 3100 miles sailed.