Answer:
I have green hair a round red head and a long thin white beard.
To cross the water I'm the way. For water I'm above I touch it not and truth to say I neither swim nor move.
I'm blue, but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt, but I'm good for you. What am I?
Before I grow I'm small. When I'm old I grow tall. When I die I give a mighty fall.
The Titanic is still here.
Give it food and it will live, give it water and it will die.