It takes a certain type of person who is willing to be on a boat for three to five months. It 是主语,takes 是谓语,person 是宾语,a certain type of 是定语修饰person,who 引导一个定语从句修饰person。从句中who是主语,is 联系动词作谓语,后面willing 是现在分词习惯用法与后面动词不定式组成表语。for three to five months是状语 修饰 be on board