JAKARTA - AS SOON as he felt the quake underneath his boat, Rick Hallet's thoughts turned to the possibility of a tsunami sweeping into the bay where his vessel was anchored off the Mentawai islands.

Scanning the sea, Mr Hallet - and the 15 others aboard his boat - saw a wall of water headed his way. Recounting the moments after the powerful 7.7 magnitude quake struck the region, which is west of Indonesia's Sumatra island.

Mr Hallet, an Australian who runs a boat-chartering business in Sumatra, said: 'We heard an almighty roar. I immediately thought of a tsunami and looked out to sea and that's when we saw the wall of white water coming at us. The bay we were in was several hundred metres across and the wall of white water was from one side to the other, it was quite scary,' he told Fairfax Radio Network.

A boat anchored next to them was first to feel the force of the surge. 'The wave picked that boat up and brought it towards us and ran straight into us and our boat exploded, caught on fire; we had a fireball on the back deck and right through the saloon within seconds,' he said.

Thinking fast, the group - including nine Australians - jumped into the water as their boat exploded. Some were swept 200 metres inland, climbing trees to get beyond the reach of the surge and waiting for more than 20 minutes for the waves to pass.

All from Mr Hallet's boat were accounted for. They were among the lucky ones. The tsunami left at least 23 dead and scores missing across remote island villages, according to local officials. Nine Australians and a Japanese man who were believed to be aboard another boat in the area were missing on Tuesday.

Aussie recalls tsunami moment