Yes, hailing early and responding with "hold your course" is the best way to handle these scenarios...though not required. It lets both boats know that the other is aware and will do what is required. By not hailing, you don't know if one boat is even aware of the other's existence. By not responding with a reply hail, one boat remains in the dark as to whether they've even been seen. This is common human courtesy. Remember, there is the letter of the law and the intent of the law...intent being to make sailing safer...which MUST be on all competitor's minds.