<p>The effects of long term, high pressure salt water exposure on the dynamic behavior of additively manufactured polymers has been investigated through an experimental study. Specifically, the compressive and flexural properties at moderate and high-rate loading before and after salt water exposure are quantified. Three additively manufactured polymers were investigated with the Material Extrusion and Vat Photopolymerization methods utilized in specimen printing. The Material Extrusion process was utilized for the generation of Markforged Nylon and Onyx specimens while Vat Photopolymerization was employed for Formlabs ClearV5 resin specimens. Specimens were exposed to 3.5% NaCl solution at a pressure of 34.5&#xa0;MPa (5000 lb/in²) for a period of 60 days to simulate deep ocean conditions on the materials. A detailed diffusion study was performed to evaluate the water uptake behavior of the respective materials under high pressure water exposure. The materials were optically evaluated through microscopy subsequent to the diffusion study to quantify changes in surface characteristics resulting from the salt water exposure. The moderate and high-rate compression and flexure behavior was evaluated on baseline specimens with no saline water exposure and on 60-day exposed material to quantify degradation of the material properties. The moderate rate testing was performed on a material testing machine and the high-rate characterization was performed through the use of a Split Hopkinson Pressure Bar (SHPB) facility. The study’s findings highlight that with increasing strain rate the material behavior stiffens while the exposure to salt water softens the same response. Thus, significant consideration must be given to material selection in marine environments which considers both the expected loading rates as well as immersion durations.</p>