The routing problem of small island ports is, in many cases, firmly dependent on country topology, e.g., how to connect islands with a main (home) port, where the order of stops can be different, especially if there are not enough passengers or cargo waiting to be transported to or from every port. Thus, we need a capable optimization tool with which we can adapt each route for an appropriate time schedule; for example, some routes in one cycle can touch each island (forwards or backwards) but some routes can be incomplete, to touch only a few of them. The carrier has to find space for price-cutting (lower prices per journey – more passengers on board), to be more attractive in free-market competition. In such route optimization, we have to interconnect minimal transport cost with maximal revenue (money from tickets), which could be a very demanding task (a non-linear objective cost function). Instead of a non-linear polynomial optimization, which can be very complicated and time-consuming, the network optimization methodology could be efficiently applied. The main goal is to find more efficient routes, to decrease expenses and to increase revenue at the same time (dual mini/max problem).