## 4 Results
### Pattern of the Departing Ship Trajectory
#### 4.2.1 Unherthing Phase  
The unherthing phase refers to the process of unherthing the vessel using tug boats, then passing Todo and the breakwater, which is plotted on the map as shown in Figure 25a, as Unherthing, Leg 1, and Turning Section 1. In passing Todo, as in the Berthing phase, the characteristics of the processes of passing on the left and right sides differed, and so they were separately marked, with the plotting results shown in Figure 25b,c. First, the case of passing Todo on the left side of the unherthing phase was analyzed. According to Figure 26a, the SOG occupies a high percentage, of over 70 counts of 0-0.5 knots during the unherthing stage. As Figure 26b indicates, the ship's speed slowly increased thereafter and, during the leg 1 stage, between 1-2 knots was noted for 106 counts, followed by 6-7 knots for 79 counts. For turning Section 1, the SOG averages 9.97 knots, and the frequency counts are as shown in Figure 26c. Figure 24: Phase designation of the departure cluster. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Scaled**} & \multicolumn{6}{c}{**Speed Over Ground**} & \multicolumn{6}{c}{**Course Over Ground**} \\ \cline{2-11}  & **Mean** & **Std.** & **Min** & **Median** & **Max** & **Mean** & **Std.** & **Min** & **Median** & **Max** \\ \hline TS 3\_1 & 8.42 & 0.81 & 6.90 & 8.40 & 11.10 & 4.99 & 6.12 & 0.00 & 3.20 & 32.40 \\ TS 3\_2 & 7.94 & 0.90 & 6.50 & 7.80 & 10.60 & 10.81 & 8.10 & 0.10 & 10.90 & 26.50 \\ TS 3\_3 & 7.65 & 0.87 & 6.20 & 7.40 & 10.20 & 24.01 & 10.16 & 4.20 & 23.20 & 42.20 \\ Leg 3\_1 & 6.80 & 1.25 & 4.00 & 6.50 & 10.10 & 40.67 & 16.62 & 0.10 & 44.00 & 73.80 \\ Leg 3\_2 & 5.97 & 1.79 & 1.20 & 5.80 & 9.40 & 51.45 & 11.30 & 19.30 & 51.20 & 79.10 \\ Leg 3\_3 & 4.96 & 2.10 & 0.50 & 5.10 & 7.90 & 44.23 & 32.18 & \(-\)87.40 & 50.75 & 78.10 \\ Leg 3\_4 & 4.06 & 1.44 & 1.20 & 4.10 & 7.10 & 32.30 & 37.44 & \(-\)49.90 & 47.10 & 69.80 \\ Berth 1 & 1.61 & 0.79 & 0.20 & 1.50 & 3.40 & 25.24 & 33.11 & \(-\)74.90 & 34.50 & 116.40 \\ Berth 2 & 0.80 & 0.41 & 0.00 & 0.80 & 2.20 & 16.10 & 39.53 & \(-\)162.90 & 22.90 & 74.90 \\ Berth 3 & 0.32 & 0.24 & 0.00 & 0.20 & 1.30 & 12.44 & 51.53 & \(-\)168.70 & 11.25 & 173.70 \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Descriptive statistics for the right-side berthing phase of the scaled time series. The result of the COG frequency counts is shown in Figure 27. First of all, arrival ships' trajectory was completed by heading north, whereas in the case of departure, ships headed south. Therefore, according to Figure 27a, which depicts the unherthing stage, the average was determined to be 192.21 degrees, and the counts also accounted for a high percentage of values between 190 and 200 degrees. After unherthing, the ships moved west to pass Todo on the left side and, accordingly, the value of COG of 270\(\sim\)280 degrees was the most frequent at 173 counts, as is shown in Figure 27b. Furthermore, as is shown in Figure 27c, in Turning Section 1, the average was almost 188.82 degrees in the breakwater phase. The range with the most counts was 190-192 degrees, reading 52 counts. The detailed descriptive statistical analysis results are shown in Table 10.  
Figure 26: Frequency analysis for the SOG of the left side unherthing phase: (**a**) Unberthing; (**b**) Leg 1; and (**c**) Turning Section 1. Figure 25: Plotting departing ships’ trajectory data on the British Admiralty Chart: (**a**) all data; (**b**) passing on left side of Todo; and (**c**) passing on right side of Todo. The time series boxplot of the unherthing phase passing Todo on the left side is shown in Figure 28. In the case of SOG, as shown in Figure 28a, it gradually increased from 0 knots, in contrast to the arrival case. However, the difference was that it increased to an average of 8.92 knots during Turning Section 1_1 (TS1_1) in the figure and an average of 10.67 knots at the final point. In the case of COG, as is shown in Figure 28b, after slowly unherthing the ship to the south, it was moved westward to pass Todo on the left side.