Complex sentence: Many sailing events are held in the waters of this country, the largest of which is a week-long series of races called the Spring Regatta, the premier sailing event of the Caribbean, with several races hosted each day.
Split into simpler sentences: Many sailing events are held in the waters of this country, the largest of which is a week-long series of races called the Spring Regatta. This is the premier sailing event of the Caribbean, with several races hosted each day.