Tom,
http://www.therecordist.com/assets/sound/mp3/rock_splash.mp3I found you a splash for the ol' Heave Ho that might be perfect, so had to share. It's got a solid dunking sound, followed by a very fancy splash that I think makes it a winner. I hope this goes at least some way towards making up for saying "truck nutz" while you were driving the bus (or is it steering the ship now?)!
Given that I didn't record this myself and I don't know the legality of using it on the radio, I leave it to your extensive broadcast experience to know if you can use it or not. I say if you still aren't getting paid for this gig, just go ahead and use it. I say you've long since earned the right and now the world should start giving a little back... but what do I know.
Joe