## 3 Results and Discussion  
Cruise traffic expansion in the central and south part of the Adriatic east coast has established new frequently used routes as navigational options to the Central Adriatic Separation Scheme. New insight into cruise ships' navigational practices was obtained by processing and analyzing data from a one-year survey of cruise ships in the Adriatic Sea from Peric (2016). The data acquired are charted in two integrated charts (Figure 9a,b). Figure 7a-e justify the data in Figure 9a,b.  
Figure 9a defines the longitudinal and transversal traffic flow of cruise ships over 50,000 GT in the Adriatic east coast. The figure shows cruise ships' routes (black lines), the well-defined North Adriatic Separation Scheme (red square 1) and the shorter, less defined Central Adriatic Separation Scheme (red square 2). The North Adriatic Separation Scheme directs the cruise traffic on steady routes without any oscillation, while the Central Adriatic Separation Scheme offers more routing options, and therefore, cruise routes are more dispersed than in the north Adriatic.  
Figure 9: (**a**) Cruise traffic in the Adriatic east coast [7]. Black lines—cruise ships’ routes; red squares—red square 1: the North Adriatic Separation Scheme; red square 2: the Central Adriatic Separation Scheme. (**b**) Cruise ships’ routes and high-risk zones in the central and south part of the east Adriatic. Black lines—cruise ships routes; red squares—red square 1: the North Adriatic Separation Scheme; red curves—marine protected areas; grey star—the island of SuSac; blue circles—areas of high navigational risks.  
According to the traffic monitoring and route analysis in the east Adriatic, cruise ships' movements can be defined in three standard patterns:  
1. From the north Adriatic ports to the central and south destination of the Adriatic east coast. Cruise ships departing from the north Adriatic ports proceed on southeasterly courses using the North Adriatic Separation Scheme. Once they leave the North Adriatic Separation Scheme, they follow the route along the outer skirts of the islands along the east Adriatic coast. They do not use the Central Adriatic Separation Scheme (Figure 7a-e).
2. From the north Adriatic ports to the Otranto strait and vice versa. Cruise ships departing from the north Adriatic ports proceed on southeasterly courses using the North Adriatic and Central Adriatic Separation scheme, heading to the Otranto strait. On northwesterly courses, cruise ships proceed from the Otranto strait to the north Adriatic ports using the Central and North Adriatic Separation Scheme (Figure 7a,c).
3. From the Otranto strait to the northern Adriatic via south Adriatic east coast destinations. Cruise ships arriving from Mediterranean ports through the Otranto strait proceed directly to the south Adriatic east coast destinations. Departing from the South Adriatic east coast destinations, cruise ships proceed in coastal navigation along the outer skirts of islands and keep out of the Central Adriatic Separation Scheme. In northwesterly courses, they join the North Adriatic Separation Scheme on the way to north Adriatic ports (Figure 7a-e).  
Cruise ships' traffic monitoring has shown irregular navigational practice where cruise ships on international voyages in transit through Croatian territorial waters (on routes: Montenegro--Italy or Mediterranean port to Italy) do not use the Central Adriatic Separation Scheme, nor are the routes planned to enable the shortest stays inside Croatian territorial waters. Cruise ships tend to choose coastal navigation between the islands in Croatian territorial waters until they reach the North Adriatic Separation Scheme (Figure 7c). The Central Adriatic Separation Scheme is only used on direct voyages from the north Adriatic ports to the Otranto strait and from the Otranto strait to north Adriatic ports.