Siargao Island Van and Motorcycle Tours
If your interests lean more to seeing the entirety of Siargao and it's less touristy areas, a van, motorcycle, or jeepnie tour of the island proper can be arranged. Many interesting natural wonders will amaze you, as well as a glimpse of the simple rural lifestyle lived by the inland inhabitants that haven't changed in generations.
Some places well worth investigating include the incredible tide pools and rock formations of Magpupungko near the town of Pilar (where the international fishing tournament is held), the waterfalls of Santa Monica, and the mangroves of Del Carmen (where it is said that large Philippine saltwater crocs still live).
Not to mention the many beaches and surf breaks from General Luna's Cloud 9 on up to Pacifico etc.