This is a follow-up Sources Sought notice for contractor support providing scientific and technical analysis of underwater and air explosions for undersea and surface vessels using specialized software. The anticipated contract is a single-award, five-year, Cost-Plus-Fixed-Fee type. The work is currently performed under existing contracts held by three different companies. Interested parties who previously responded must reaffirm their interest via email and resubmit updated documents if applicable. Responses to the attached market research questionnaire and SOW questions are requested by 21 April 2026.