"tepelikli" is the reference for the shape of the buoy top. Your guess was partially correct, except "ışıklı" is "lighted" instead of "light". Although I haven't seen this term used in any of the United States navigation guides that I have (I am also a boater and sailor), this term can be translated as "West cardinal top lighted column buoy" or "West cardinal top lighted buoy" since or light buoys are column shape.