关于扩展一的港口，规则上说若打下港口所属城市，里面敌军的舰队自动换成你的舰队，不过受到补给限制，假设对方原先有一只舰队在港口，如果受补给限制或者手头舰队使用完毕，不能进行替换，是不是原先的舰队得以保留，且在下回合攻入方不能再摧毁他们，原文如下：
Such an invading player may choose not to take over the ships in the port and destroy them immediately after invading the land area. If the player does decide to take the ships, however, he may not choose to destroy them at a later time
