Renting a boat is the quickest way to reach Port Barton from San Vicente, however, if the weather is adverse the boats may not be operating and you might get stuck in San Vicente. You could then travel on land but this trip is complicated and will take 4 to 5 hours.
After landing take a tricycle to the local peer in Poblacion San Vicente and look for a boat service. The boat is PHP 3000 for 4 people (if you are alone and there are no other travelers you still have to pay PHP3000 but if there are 4 of you it will be 750 only).
The route is San Vicente-Roxas-Port Barton or San Vicente-San Jose Junction-Port Barton. If you go through Roxas you need to make sure that you are in there before the noon to catch the only jepney that leaves for Port Barton from the terminal at 12.00 a.m. If you go through the San Jose Junction you can take any van or bus that goes to the national highway. If it goes to Puerto Princesa you need to get off at the junction and catch a van going to Port Barton. If it goes to El Nido you need to get off on the national highway, catch anything that will give you a lift to the San Jose Junction and then catch the van to Port Barton. Be careful when you ask to go to San Jose. Make sure it is San Jose Junction 23 km from Port Barton not Sun Jose terminal in Puerto Princesa which is some 150 km further south.