This diving animation consists of a 5-frame sequence for the dive, plus one frame for the tank by itself, and another for the tank containing the large splash following the dive.

I started out with a scanned pencil-line drawing of the movements, as for my frog animation.  Then the line drawings were separated out, cleaned up and colored. 

Here are the colored images that I produced:

Because each frame is a rectangle, I needed to include the part of the tank in the dive frames where these frames overwrite a part of the background tank.

When creating this animation, the tank was placed in a background layer, and the dive movements were placed in a foreground layer.  The initial frame containing the tank takes the full drawing-space size.  The other frames are smaller, and contain just the parts of the image which change from one frame to the next. This helps to keep the GIF file small.

Each frame, in addition to showing the next movement, has to clean up the mess left by the previous frame.  

There are two parts to this cleanup operation.  The image must be removed, and also the original background must be put back. You can create the frames to do this yourself, but it is a lot of work.  Future Splash Animator handled this for me.  The frame shown here is one of those that was generated for me. The blank space in the rectangle wipes out the previous dive frame.

This animation was created using Future Splash Animator, and then it was edited using GIF Construction Set in order to put in the delays between the dives.