Flora and fauna
You can use the ferry that starts in Singkil every Tuesday. It departs at about 11AM. You must buy tickets in the harbour for 25.000 Rupiah. You can also bring your Motorbike to the island for additional 50.000 Rupiah. After about 4 hours you will get to the Island called Balai (the island group is called Banyak). There are also many cargo ships to and from Balai, it is usually no problem to get on those cargo ships, but there is no departure schedule. The price is the same. Another way to get to any island is using Speedboats. They cost 1.000.000 Rupiah and they drive on demand.
Please Note: There is no ATM on Banyak. In Singkil there is no ATM that takes VISA (not sure if Mastercard works). Even in bigger neighbour cities it is impossible to find ATMs that accepts VISA. It is strongly advisable to take enough Rupiah to Banyak. If you ask around you find people that exchange Euros and Dollars but under very bad conditions.
At the moment 16/12/13 the ferry from Singkil to Balai is out of service due to damage. There is no scheduled time of returning to operation.
You can visit most of the Islands around Banyak. For Islands that are near Balai you can ask fishermen to drive you there, they usually give you a rather good price. It is also possible to go by Speedboat, they are much faster, but also more expensive.
Banyak Surf Bungalows +62 81361263491  offers boat tours that visit selected (depending on swell direction and size) "closely guarded secret spots", in and around the 70 Banyak Islands (their main area of operation).
It is possible to go fishing with locals. Simply ask around an you are likely to find a fisher that brings you to the see.
Palambak Island : bungalows, snorkelling, kayaking & relaxing
The official ferry to Singkil is scheduled on Wednesday. But there are Cargo-ships returning to Singkil everyday. Simply ask in the harbour how you can get onto the cargo ships. Prices for the Cargo or the ferry (without a motorbike) are at 25,000 Rupiah.