Elijah E. Cummings Merchant Mariner Workforce Development Act This bill directs the Department of Transportation (DOT) to establish the Elijah E. Cummings Merchant Mariner Career Training Loan Program to make loans available to certain students for the training of U.S. merchant mariners, including those working to receive a Standards of Training, Certification and Watchkeeping endorsement. The program shall be administered by the U.S. Maritime Administration (MARAD). MARAD may not make loans to a student under the program in an amount that exceeds $30,000 in a calendar year or $120,000 in the aggregate. MARAD must publish a plan to recruit, train, and retain merchant mariners, including (1) a strategy to address merchant mariner recruitment, training, and retention issues in the United States; and (2) demonstration and research priorities concerning such issues. Additionally, DOT may award competitive grants to, or enter into contracts or cooperative agreements with, maritime training institutions to carry out demonstration and research projects that implement the priorities identified in the plan for the purpose of recruiting, training, or retaining U.S. merchant mariners.