Thanks to your interest M Ross and Trevor. I am finding morethat mention fairly lage number of German immigrants around this time, and the Caroline Islands you mention were possibly the place, given Charlestown was less known (founded in 1670) and that the islands around it James, John, Sullivan were better known. Even Charlestown is on an islet.
This area and immigration looks like a One Place Study waiting for me to write it. after I aske the question, (as it usually happpens) I discovered many documents and writings about the early settlement there.
So, the Sea Captain's just grouped the whole area into the words "Carolina Islands", it doth appear.