Mars may have had an ocean up to 3.5 billion years ago, and preserved shorelines from that ocean are debated. Paleoshorelines on Earth are observed as subtle topographic features. A Python diffusion model was run at Mars-like diffusivity values across 3.5 billion years, on topographic data of preserved shorelines from paleolake Bonneville, to test the efficacy of preserving these subtle features. Depending on their size and the diffusivity values, shorelines may or may not persist.