mkd20012001
Live~Love~Laugh
You are correct, you didn't have enough light and the camera took the pictures with a high ISO(producing the noise) and a slow shutter speed(giving you the blur). You will have to be in pretty bright clear water to get pictures to not be so blurry.
Look at some sites, you may find something that helps.
The water was clear as can be, but it was overcast the majority of our trip.