Rayner’s Rock or Batu Ronchek is located at the most northerly point of Telok Jawa. It is a large rock awash just at the opening of The Channel. Here divers’ can experience swimming with mantas, whale sharks, bumphead parrotfish and other huge pelagic.
The word Ronchek is not easy to interpret. It may be a variant of Ronce (Ronche) that means robbing or taking away by force.
The site offers a very good drift dive, best done from a boat. Moderate currents are ideal especially when set from north to south past the rock. The current carries the diver southwards towards and past the rock on its seaward face, much exciting than the shallower inshore side.
Here also are coral garden flats set in bedrock plus sea whips and scraps of corals. More over, a sheer rock slope leads the seaward flank of the rock where pelagic are usually looked out for. The more fascinating is the southern flank of the rock where you will find a spectacular jumble of huge blocks and boulders as well as plenty large grottoes and swim-throughs.