“One particular boat is obvious astern of another when her hull and machines in normal placement are powering a line abeam from the aftermost position of one other boat’s hull and products in regular position. The opposite boat is evident in advance. They overlap when neither is evident astern. [snip] https://www.whofish.org/Default.aspx?tabid=45&modid=379&action=detail&itemid=310505&rCode=18