Background <p>Understanding the dynamic buckling behavior of cylindrical shells is crucial for various marine engineering applications including underwater pipelines, yet the influence of concave circumferential grooves on their collapse capacity remains underexplored.</p> Objective <p>This study aims to investigate the effect of groove geometry on the dynamic buckling behavior of aluminum tubes under hydrostatic pressure.</p> Methods <p>Experiments were conducted in a water-filled pressure vessel facility, utilizing high-speed imaging with 3D Digital Image Correlation and piezoelectric transducers to capture transient collapse behavior of cylindrical shells and associated local pressure histories. Finite element simulations complemented the experiments to analyze critical pressure sensitivity to groove wall thickness.</p> Results <p>The presence of a mid-length groove increased collapse capacity by 25% to 50% compared to non-grooved tubes and reduced peak dynamic overpressure. Groove depth significantly influenced failure mode: deeper grooves induced local buckling, while shallow grooves led to global collapse. Simulations further demonstrated collapse capacity improvements reaching up to 65% for tubes with a groove.</p> Conclusions <p>Introducing a concave circumferential groove enhances the collapse resistance of cylindrical shells, with geometric configuration playing a pivotal role in determining failure mode.</p>