Trekking
Except snorkeling and diving the only thing you can do if you are fed up with chilling out on the beach is trekking in the jungle. The only advice I can tell you is that you'll need a lot of water and good shoes.
Hishaam crushed on a sharp rock our only bottle of water after 100m inside the jungle and all of us were wearing slippers...We wanted to go from Salang to ABC (air batang) and after trekking 1hour and half inside the majestic rainforest, slipping at every step, sweating like hell, enjoying the 99% of humidity we finally reached...the first third of the way: Monkey Bay... No monkeys on the beach (even though we saw one in the forest) but at least I was a nice play to rest. Absolutely nobody was there and it was like our recompense after such a trek. Some houses were forsaken, and we could really feel in the middle of nowhere.
After talking about whether or not we should keep going until ABC we decided to come back to Salang. We didn't had any water for the past 1hour and half, and 1hour half to walk back, didn't know exactly how long it would take to reach ABC and above all we had 3hours before the ferry leaves Tioman back to Mersing.
That was the best solution to take and at least we had time to get lunch and drink water (rhaaaaaa, finally).