Poptropica Walkthrough - SOS Island Part 2 - Rescuing the Engineer

After rescuing the cruise director, you return to the ship.  Go left, and climb the platforms formed by open windows. Keep jumping on them, reach a rope and climb it, then keep jumping on the windows. Get to the top of the ship and enter through a hole. You will fall deep in water. Swim up and avoid the metal pipes that give you an electric shock. Make sure to watch the oxygen level on the bottom of the screen.

You will reach a series of pipes, use the yellow arrow to make water move through them. It will blow up a hole and lower some equipment which you can climb up. Keep jumping up, working your way to the top. The engineer there tells you to be careful, you can't get through the steam. We need to reduce the pressure. After she turns this valve, she wants you to get to the other side and turn the other valve before the pressure builds.

Go to the left of the room and watch the water flow through the pipes. The engineer tells you that there are three other pipes, you need to find them and do the same thing. Locate the other valves in that room and turn them. There is one in the lower right corner of the room, and some more to the left of the room, one to the right of the room, and another one to the left of the room underneath the first one.

Once you have turned them all, go back and speak with the engineer. She thanks you for getting the steam off. Now she can fix the ship.

You can say:
It's too late to fix the ship!
It's taken on too much water, it's going down.
Oh Uh, the captain told me to come down here and tell you to leave

You need to convince her to get off the ship. Choose the third option. Since Captain Boomer gave the order, she agrees to come with you. When you are out of the ship you tell her that you lied, the captain didn't order her off the ship.  She is upset that you deceived her, but still thanks you for saving her life. She gives you a tool: Pipe Wrench

In the meantime the ship takes a nose dive. She tells you to get back to the ship and look for others.