在海岸\(A\)处,发现北偏东\(45^{\circ}\)方向,距离\(A( \sqrt {3}-1)nmile\)的\(B\)处有一艘走私船,在\(A\)处北偏西\(75^{\circ}\)的方向,距离\(A2nmile\)的\(C\)处的缉私船奉命以\(10 \sqrt {3}nmile/h\)的速度追截走私船,此时,走私船正以\(10nmile/h\)的速度从\(B\)处向北偏东\(30^{\circ}\)方向逃窜.
\((1)\)求线段\(BC\)的长度;
\((2)\)求\(∠ACB\)的大小;
\((\)参考数值:\(\sin 15 ^{\circ} = \dfrac { \sqrt {6}- \sqrt {2}}{4},\cos 15 ^{\circ} = \dfrac { \sqrt {6}+ \sqrt {2}}{4})\)
\((3)\)问缉私船沿北偏东多少度的方向能最快追上走私船?