Maritime Autonomous Surface Ships (MASSs) are expected to become vital participants in future maritime commerce and ocean development activities. This paper investigates a channel capacity-based scheme for estimating the persistence of ship-to-ship communication links in MASS communication scenarios. Specifically, this study presents a relative motion model for nodes within the network and estimates link persistence based on the dynamic characteristics of the links. Additionally, transmission modes tailored to maritime communication scenarios are proposed to optimize link capacity and reduce interference. Simulation results demonstrate that the proposed method can accurately estimate the duration and capacity of the links, thereby achieving higher network capacity. When used as a metric for routing protocols, the proposed link-persistence measure outperforms traditional metrics in terms of packet loss ratio, end-to-end delay, and throughput. Comparisons with other mobility models show that the proposed mobility model offers greater accuracy and reliability in describing the relative mobility of nodes.