A good tutorial on wakes and foam here: http://www.paroge.com/vde/tutorial/default.htm I can also recommend "Sea Vue" by Monsoon - available over at 3dCommune.com, it has some very good effects in it. For a simple wake I sometimes use the text letter "V". Make it big, round the edges, apply a foam texture and position carefully. It will only work with a sea made from a terrain rather than a water plane, but with a bit of effort it can be quite effective.