I have just found out an ancestor, Silas Emmanuel Wilkes was a crew member aboard the SS Orbita which was a mail ship between Hamburg - NY (via Southampton and Cherbourg).
He docked in NY on 1st December and was listed as a deserting seaman.
I can find no trace of him in the US Federal Census 1930 and no trace of him in any passenger list returning to the UK.
What would have happened to illegal immigrants in the US in the 1920's? I am guessing he maybe changed his name