Croatia has a very good ferry system, and ferry schedules are fairly reliable (just be sure you double check any ferry information you get off the web once you arrive in Croatia). Rab Island was one of many stops we made along the Croatia's coastal road as we headed south from Opatija to Dubrovnik in our little rental car. The tiny town of Jablanac is where you catch the Car Ferry run by the Rapska Plovidba Ferry company to Misnjak on Rab. It's a short ride - about a 15 minutes, and the cost is minimal - about $8 USD per car (70 kuna); plus an additional $1 USD (9 kuna) per person. Ferries run regularly on the hour, but it is a very good idea to double check the ferry schedules before you plan your whole day around a specific departure time.
A Sample Ferry Schedule
In September 2000, the ferries from Jablanac were running every hour (leaving Jablanac at 11:00 a.m.; arriving in Misnjak at 11:15; re-loading then returning to Jablanac for another boatload at noon). At that time of year, ferries service began at 5:30 a.m. through 8:30 p.m. In the peak seasons of July and August ferries run from Jablanac starting at 5:30 a.m. through 11:00 p.m. These times are from the 2000 schedule - so be sure to check with a tourist office in Croatia for a current schedule. The best ferry schedule I could find for your reference on the web is on this website: http://www.cts.hr/tedi/english.htm. To date, Rapska Plovidba does not seem to have their own website.
What to do When You Get to Jablanac
When you drive down the hill into Jablanac, you will queue your car up and wait for the signal from the ferry crew to load. The crew is very efficient in directing even the most clueless drivers onto the boat, and they can really pack them in! Once you've parked your car in the outdoor loading area, you are free to get out and enjoy the quick ride over to Rab Island. The ferry will approach Rab's karstic side (almost half of Rab Island is covered with karst - barren fields of porous limestone), so it looks like you are docking on the moon. Once you get back in your car and disembark it's only a short drive till you reach the beautiful, lush side of the island. Rab Town is only about 15 minutes from Misnjak, and there's basically only one road, so you can't get lost. The ferry folks will give you a map of the island when you buy your ferry tickets.