OK, I misunderstood what was being edited here. He didn't mention that he was editing an effect named "voo_heat_shimmer_helo1.fx" in his original postings. I thought he was editing an existing wake effect and I now realize that the shimmer effect has a call for a wake texture in the code. Sorry 'bout that. My mistake.
BTW, what transparency level setting did you end up using?
Steve