Stay out of its way! By "large vessel" you mean something like a cargo ship? If you are in a small craft and the other guy is in a ship, assume, unless he gives a signal to acknowledge he sees you (like blowing his horn, flashing lights, etc) that he doesn't see you. If he can't see you and you get in his way, he'll probably squash you flat.
power boat
A power boat cannot stop or turn as fast, especially a vessel larger than the sail boat . The sail boat should give way to the power boat.
When a sail boat overtakes a power boat the power boat is the stand on vessel.
power boat
The red light should be on the right side, or port side, of the boat. The green light should be on the left, or starboard, side of the boat.
The Jet ski is the give-way vessel.
power boat
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 powerboat. The vessel that has the greatest ability to get out of the way of the other one has the duty to do that.
The overtaking vessel must always give way. Therefore the powerboat must be prepared to stop or change direction - the sailboat has right of way.
the power driven ship should give-way, and it must only do so by turning starboard... in good seamanship the sailing vessel should also turn starboard, but are not required to by law.
When one boat overtakes another, the overtaking vessel is considered the give-way vessel no matter what it's powered by.