Ok Lets begin-

Open your your three image into photoshop..

We will be the bulb first. this will be your background image.

Please note

What I did was:

add vector mask to the baby layer, please make sure you have this layer with your bulb background.

Use a soft brush and erase the red area around the baby.

Or you can use the pentool to get a better cut.

You should have something like this..

It doesn't have to be perfect

.

Once the image is all combine you should have something thing like this. Move the baby where you want the baby to be.

Now we are going to add the water, place the blue water image as shown to the left.

Simple so far right.

OK now that you have the image on top of the bulb apply "screen" as that layer effect. This will lighten your image. Now we need to erase the edges around the bulb.

To do this choose a soft brush, lower the opacity and your done.