Motivated by a learners' general lack of engagement and passive receiving of information from lectures, and the increased use of interactive media from the millennial generation, the author investigated the interaction effect of immersive virtual reality (VR) in the classroom. The objective of the project was to develop and provide a low-cost, scalable, and portable VR system containing purposely designed and developed immersive virtual learning environments for the U.S. Army. The purpose of the mixed design experiment was to compare lecture-based and immersive VR-based multimedia instruction, in terms of declarative knowledge acquisition (i.e. learning) of basic corrosion prevention and control with military personnel. Participants were randomly assigned to the control group (N = 115) or investigational group (N = 25) and tested immediately before and after training. The author accessed learning outcomes from the pre- and post-exam scores and VR system usability from exit questionnaires. Results indicate that both forms of instruction will increase learning. VR-based did produce higher gain scores and there was a statistically significant interaction between instruction type and time. Lecture-based instruction continues to be a cheaper and more efficient method for large group settings while VR-based instruction advocates individual training, active learning, and condensed training time.