Introduction The burden of alcohol misuse is unknown among shipboard U.S. Navy and Marine Corps military personnel immediately prior to deployment and may be elevated. Methods Anonymous survey data on hazardous, dependent, and binge alcohol misuse and involuntary drug consumption were collected during 2012–2014 among shipboard personnel within approximately 2 weeks of deployment. Using the Alcohol Use Disorders Identification Test Consumption (AUDIT-C), hazardous alcohol misuse was defined using two cut-point scoring criteria: (1) ≥3 for women and ≥4 for men; and (2) ≥4 for women and ≥5 for men; binge drinking as ≥4 drinks for women and ≥5 drinks for men on a typical day in past 30 days; and dependent alcohol misuse as an AUDIT-C score of ≥8. Demographic- and sex-stratified self-reported alcohol misuse prevalence was reported for analysis conducted during 2014–2015. Results Among 2,351 male and female shipboard personnel, 39%–54% screened positive for hazardous, 27% for binge, and 15% for dependent alcohol use. Seven percent reported involuntary drug consumption history. A larger proportion of those aged 17–20 years screened positive for dependent alcohol use compared with the overall study population prevalence. Conclusions A large proportion of shipboard personnel screened positive for hazardous and dependent alcohol use (18% among those aged <21 years) at deployment onset. These data can inform interventions targeting shipboard personnel engaging in hazardous use before progression to dependent use and enable early identification and care for dependent users. Future studies should include more comprehensive assessment of factors associated with involuntary drug consumption.