Dave_W wrote:
Foam divers for bass are a pattern I have put a lot of time and experimentation into. After a lot of failures (they look great in the vise, but don't perform well in the water) essentially, what I've come to discover is that you need a form of counterweight. Keep in mind that this isn't a surface fly - you need a body that is somewhat heavy and water absorbent. I use some lead wrappings in conjunction with fur. This counteracts the flotational aspect of the foam head and "rights" the fly at the surface. Then when you strip, the fly "digs" downward below the surface producing the action you seek.
If you have a bathtub, fill it with a few inches of water and practice with your diver patterns to first solve the problem of getting it to float right-side-up. Then practice with head shape to get the dive effect. This will take some experimentation.