The captain should open his eyes and see which are blue. I am assuming he isn't colour blind.

>There are three men on a deserted island.
>The men on the island are either Red or Blue.
>
>Red people always tell lies.
>Blue people always tell the truth.
>
>A ship comes to rescue them and the captain of the ships shoult to the men, "We will only rescue Blue people."
>
>Man A says, "I'm blue and those two are "red".
>Man B says something but it was blown away with the wind.
>Man C Says, "B said he's Blue. That's true. I'm blue too."
>
>Which of the three men should take if he wants just blue people and why?