In this report, the second phase of a three-year study by the Committee on Maritime Advanced Information Systems of the National Research Council, a strategy is presented for overcoming the major barriers and deficiencies and providing a minimum level of maritime safety information nationwide. In this phase of the study, the committee concentrated on maritime information systems that promote safety, which is the area of greatest need. The committee did not examine in detail the relationship between navigation safety and maritime transportation efficiency or evaluate information systems that promote efficiency; the committee believes, however, that these issues deserve further attention.