Five seamounts (Denson, Dickins, Pratt, Welker and Giacomini) in the Gulf of Alaska that had not previously been observed by manned submersible or ROV were thoroughly mapped with multi-beaming and their fauna explored by a scientific party of 25 participating in the 2004 Gulf of Alaska Seamount Expedition. An estimated 43 coral species and 21 sponge species were collected and identified from 17 dives made by the DSV ALVIN on 5 seamounts. A large number of coral specimens were processed and packaged and sent the National Museum of Natural History, Smithsonian Institution upon disembarkation. Faunal assemblages on the corals included species from 12 different phyla and a large number (hundreds) of lesser taxa. Many of these species represent significant range extensions or records of undescribed species, but await post-cruise processing for identification and clarification. Plasma and tissue samples for genetic and physiological examination were collected from >120 crab specimens belonging to a number of species; tissue samples were collected from >130 shrimp for genetic studies. Samples of 62 coral specimens (22 bamboo, 15 paragorgid, 19 primnoid, 7 black, 23 other), 13 sponge specimens, and 36 water samples were collected for genomic studies of bacterial communities. 58 basaltic rocks were collected for geological studies and 4 rocks were collected for microbiological studies. Detailed mapping of the study area resulted in 14081 km2 of seamounts multibeamed, plus 9000 km2 of seafloor mapped while in transit, equaling 23081 km2 of total seafloor mapped. Education and outreach activities associated with the 2004 Gulf of Alaska Seamount Expedition were extensive, and included an NOAA Ocean Explorer Web site; lesson plans; a Professional Development Institutes (PDI) for Educators; 5 interactive satellite telephone calls to schools or institutes, which included conversations with scientists in situ aboard the Alvin; an Educator at Sea (Carey DeLauder, UCAP Science Teacher); nine undergradute and graduate students, a Dean John A. Knauss Sea Grant Fellow (Nicholas Alvarado), and a MATE Intern (Shinobu Okano) participated in the cruise; and, a media event at the termination of the cruise was held in Astoria, Oregon for public school teachers, newspaper, radio and television reporters. All aspects of the cruise were well documented, and all dives were designed to be multipurpose and collect data for all participants. The cruise was a resounding success and will produce a multitude of scientific discoveries.