Battery-powered propulsion has emerged as a promising solution for inland waterway freight transportation. However, the range anxiety caused by limited energy density of batteries remains a major obstacle to the widespread adoption of inland electric ships. To address this challenge, strategic energy replenishment through either recharging or battery swapping is crucial. Prior studies have explored the joint optimization of energy replenishment strategy and sailing speed for inland electric ships with the objective of cost minimization but lacking flexibility in technology selection and energy replenishment amount determination. This study proposes an innovative approach to jointly optimize energy replenishment strategies and sailing speeds for inland electric ships, extending existing methods by incorporating both recharging and battery swapping options while allowing flexibility in determining energy replenishment amounts. The problem is formulated as a mixed-integer linear programming (MILP) model, utilizing linearization and speed discretization to minimize total energy replenishment costs. The proposed methodology is validated through a case study of a 700-TEU electric container ship operating on the Nanjing-Yangshan route, demonstrating its effectiveness by achieving up to 9% cost reduction and im-proved solution feasibility.