The ship that has the other ship on its starboard side needs to steer clear, while the other ship should maintain course and speed.
The ship that needs to steer clear should if possible make a maneuver so big that the other ship has no doubt that a maneuver has been executed...
ETA:
Rules of the Road
International
Steering and Sailing Rules
Rule 15
Crossing situation
When two power driven vessels are crossing so as to involve the risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.
Inland
(a) When two power driven vessels are crossing so as to involve the risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.
(b) Nothwithstanding paragraph (a), on the Great Lakes, Western Rivers, or water specified by the Secretary, and proceeding downbound with a following current shall have the right-of-way over an upbound vessel, shall propose the manner of passage, and shall initiate the maneuvering signals prescribed by rule 34 (a) (i), as appropriate.
How the two vessels are propelled
vessels operator
the vessel operator
Starboard ( right side ) and it should be mounted so it is visible at 135 degrees .
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.
A sailing vessel operator should sound a blast on the horn when approaching a PWC head on. However, it is up to the operator of the motorized craft, in this case the PWC, to take evasive action.
The coast guard sets regulations for what safety equipment a vessel requires based on length. The vessels operator is responsible for measuring and making sure the appropriate equipment is on board.
Stay far enough away that the large vessel's helmsman can see you.
Vessel,s are that is water vessels