its an interesting idea, although slightly badly drawn, if you may allow me saying so.

the best way to fix this issue, is by drawing the madness characters as simple geometrical shapes.
try drawing ovals in flash for their heads, and a rough rectangle for their bodies, while you can draw some simple circles with lines for their hands, and some basic gun models by studying some pics online (or by doing some basic L-shaped guns with lines in flash)...

when you will have your basic characters +designs ready, prepare to draw some simple, yet more quality-drawn backgrounds, drawn with lines in the important objects of the scene, (for example the ship+the control panel of the ship), and using thick (or narrow) brushes for the background (for example, the sea+the sea floor)...

that way, you will be able to better portray your story, because it certainly sounds interesting, and i would like to see more about this, and/or more stuff like this.

also your sea-monster/guardian/ursula, needs to be more detailed, while it should be slightly different than tricky the clown in her design...

anyways, this was a promising movie, and i hope that you will slowly improve over time with practice, because this is a very promising script, and its pretty original for a madness movie.
keep up the good work!