There are many websites at which you can learn the "rules of the road".
Regardless of these it is always a requirement to maintain safety at all times. I have been sailing for more than thirty years and if I was in such a poistion I would go astern of the other boat so long as it was safe to to so or simply slow down and allow him to clear.
when the power-driven vessel is towing another boat and has difficulty maneuvering
Assuming you are referring to a fog horn or a warning signal, generally find where the other vessel is and change course accordingly
Be alert and observant.Scan 360 degrees and act accordingly. ALWAYS look before you leap.
the vessel operator
Starboard ( right side ) and it should be mounted so it is visible at 135 degrees .
The power-driven vessel should change course and speed.
Steer into the wind.
Keep clear... The power driven vessel should, if possible, maintain course and speed. The only rule for overtaking is that you keep your distance while overtaking
A sailing vessel operator when approaching a pwc head on should slow down and change course.
the vessel operator
When approaching a sailing vessel head on, it is up to the motorboat to yield. The motorboat operator should swing wide as early as possible to stay well clear of the sailing vessel.
The sailboat operator is the stand-on vessel so they should keep their course and speed while the PWC is the give-away vessel so it should change course and speed.