You can get to island of Hvar by ferryboat to town of Stari Grad, there you can take one of the regular line buses, taxies or by your own car to town of Hvar which is like 20 km from there.
Since the port of Hvar is too small to accept the ferryboats you have catamarans which are going daily 3 or 4 times from the port of Split directly to the port of Hvar. It will take you around 50 min to get there.