They had checked out the shipwreck with robotic ones, but now it was time to send a human down in a what?\nOptions:\n- rowboat\n- chair\n- school\n- submarine\n- internet cafe
Let's be accurate as possible and think first.
submarine
Shipwreck is found generally under water in a sea.

Humans can go down in a sea in submarine.

.

The final answer: submarine