how would you write "it will take 3 times longer to go by airplane than by boat"? i know 세배 is "three times" and i have an idea of the construction for "noun a is [adjective]er than [noun b]" (using 보다 더) and i know about 걸립니다, but i don't understand what i should make the subject here, or the adjective for "longer" with regard to 걸립니다.

thanks!