This study presents an investigation into the propagation of modified anomalous vortex beams (MAVBs) through maritime atmospheric turbulence. We introduce and validate analytical formulations using Extended Huygens–Fresnel integral to accurately model MAVB propagation under unique conditions of maritime turbulence, representing a critical advancement for optical communication in this challenging environment. These theoretical predictions are rigorously assessed against both multi–phase screen numerical simulations and 1000-meter scaled experimental measurements, employing a five-spatial light modulator (SLM) setup for beam generation, turbulence simulation and measuring orbital angular momentum (OAM) spectrum. Under weak turbulence, excellent agreement is observed across all three approaches, unequivocally confirming the validity of our analytical model. However, a divergence from the analytical solution emerges under stronger turbulence, underscoring the limitations of conventional integral approximation models in highly dynamic marine environments. We also systematically quantify maritime turbulence’s impact on the OAM spectrum via modal decomposition. This provides empirical evidence of MAVBs’ OAM mode resilience and degradation, informing the design of OAM-multiplexed free-space optical communication systems for challenging maritime conditions.