When you become a boater, you become part of the wider boating community.
You'll find yourself waving at boaters that you've never met before, and you'll also render assistance if you see another boater in trouble.
Not only is it a nice thing to do, it's one of your responsibilities as a boater. So, if you see an accident, or a distress signal, you need to render assistance any way you can, as long as you can do so without endangering yourself, your passengers or your vessel.
If you cannot help out safely, make sure to notify another boater who can as quickly as possible; and also notify the authorities.
If you are involved in an accident with another boat, you need to stop and exchange information—and provide assistance if you can do so safely. You'll learn more in the course's video on accident reporting.