Current time Mersing Harbour Centre:
If you're going to Pulau Rawa, Pulau Besar, Pulau Tenga, Pulau Dayang and Pulau Aur, then you won't need to book your ferry separately. Once you've booked your hotel or resort on the respective island, the hotel or resort staff will arrange for a ferry pick-up from Mersing, usually by private speedboat, to the hotel or resort in question. Naturally, they will also ensure that you get ferried back to Mersing upon checking out of the hotel or resort.
The boat ride rarely lasts longer than 20-30 minutes.
However, in most cases, the ferry to Pulau Tioman needs to be booked separately, as most of Tioman's hotels and/or resorts do not have the resources to operate a ferry of their own. The reason for this is that Tioman is located quite a bit further offshore and, as such, requires a properly certified sea-worthy vessel to operate safely.
This ferry journey can be up to two hours or longer, depending on weather and state of the sea.
If you're going to Pulau Tioman, you can book your tickets here.