day trip to Hvar from Split
 

I am planning 2-3 days in Split in May and wonder if it is possible to do a day trip to Hvar? What are the best options- catamaran, charter boat, ferry.... for transport. Is the frequency and availability enough that we can just plan it when we get there? Thanks

I'm not sure that ferries would be an option - as I recall, the options are still rather limited in May. You might search this board for posts by Mimar, who I think has recently provided links to the ferry schedules.

Split to Brac is open and the town is pretty

Search your dates at http://www.jadrolinija.hr/default.aspx?lang=2.
Note you may need to take the ferry to Stari Grad, a place worth seeing in its own right, and then take a bus to Hvar town. Be sure to check the return times to make sure you can get back and that you'll have enough time. There are daily boats, I just don't know if they run at times convenient for a day trip.

Ferries might make it hard for a day trip as yorkshire mentions above. There are ferries and catamarans into Hvar Town but they all seem to arrive in the afternoon. Will you have a car? If so, then take the car ferry to Stari Grad.

There are outfits that do day tours - you could go that route.
http://www.split-excursions.com/

Or do a day trip where the connections are easier, like Trogir.