Shark-Induced Flatulence

The little bit of silliness which you can see above, was my contribution to this week's caption competition. The theme was Scuba Diving. Members of my family will attest, with some amusement, that I am congenitally unable to pronounce the the word 'scuba' properly. This is, of course, arrant nonsense and it should go without saying that my pronunciation is the correct one.
That aside, I came joint second with fifteen points; a fact of which I am exceedingly proud.
Now then, nuts and bolts. It is inked over pencils on run-of-the-mill photocopy paper. It was drawn against the clock on a fairly busy Sunday morning, but I knew pretty much what I was going to draw a couple of days beforehand. I was going to draw the diver and shark 3/4 facing the viewer, so that we would see the shark from behind, with the diver slightly facing the viewer. I did a very, VERY rough sketch based on that idea, but felt that it would dissipate the image. I decided on a side-on image and a slow-burn left to right reading of the gag. This cartooning lark isn't just a few seconds slap-dash scribbling you know!
Upon taking cognizance of the subject, the baser parts of my imagination came naturally rushing to the fore. Was there some inevitability for my score? I believe so. It is a universal dictum that all farts are funny. So ner!