Via Penang Port Swettenham, there's one place you can go, that is Langkawi Island.

from Penang to Langkawi Island via Langkawi ferry is about 2 hour 30 min, one of my priority job is to drive my passengers to and fro Langkawi Jetty.

You can rent a chalet at the beach resort or simply go for a self-guided tour around the island