South Sumatra is still relatively untouched by mainstream tourism. Searching for waves in the area can really provide that old school surf adventure with consistent surf and zero crowds away from the main breaks.
If you are planning to get off the beaten track and do some exploration of your own it is a good idea to have a guide or speak a little Bahasa Indonesian as you could find yourself venturing to some remote areas in search of the perfect wave . The main surf season runs from March through to November. This fits in with the prevailing trade winds which blow offshore this time of year.