I sailed with an ex-WWII destroyer commander who seemed to know what he was doing. When calling unidentifiable vessels on the
radio at sea, the protocol was to hail: "Tanker" (or whatever type of vessel it was, if we could determine it)"bearing xxx degrees True, "Tanker bearing xxx degrees True, this is the yacht yyyyy ". Then we'd add details like the distance we thought we were, and if we were off his port beam, bow, or whatever, tell him what we wanted him to know about our heading and speed, and ask him if how he was planning to pass us and if we could do anything to make that easier for him.
The 'Old Man' said that using a True
compass bearing makes it easier for a ship to find you because they use gyrocompasses, not magnetic ones. Telling him where to look in relation to his
hull also helps him find you. Advising him your intentions right off gives him an idea of what you might do - sailboats are known to do screwy things as far as ship's officers are concerned. Asking him how he expects to deal with the crossing subtly hints that he already has a plan, and so obviously has competent officers on watch who were already aware of you. (Maybe!) We spoke this way with tankers,
research vessels and ferries on our transatlantic trip to
Europe.