I think I will go for an image of the dramatic episode where Wuphon's Dream is snatched by a metallic "sea monster". The only problem is that I have never really tried to imagin the way they really look, beside the description in the book. I have to do some research!!
I know that the challengers may use the uplift serie as an inspiration for an alien interaction theme, but I think I will take the idea directly from the story as the friendship between the 4 in the sub is the best example for an alien interaction.