Best missed out on a place in the open division after breaking a board in a heat and having to ride his spare.

The world title went to Emerald Beach local Rees Duncan jnr, who also won the seniors.

Best's sister Lauren, of Dromana, was equal fifth in the women's division. She began competition wave ski surfing a year ago when the Australian titles were held at Rye.

The mainly one-metre-plus waves at Emerald Beach were surfed in the seven-day event by more than 100 competitors from Australia, New Zealand, mainland United States, Hawaii, Guadalupe, Peru, Reunion Island, France, United Kingdom and South Africa.

Best will defend his Australian title in mid-2010 on the south coast of NSW and go the South Africa for the next worlds title in 2011.

Although he missed out on the title, Best, who made boards for himself and his sister in the week leading up to the titles, says his broken board had taught him a few lessons.

"I know the areas that need strengthening. I broke the ski when the tide was low. I was sucked over the falls and kinda cartwheeled over backwards, hitting my head on the sand.

"That first wave weakened the board and the following wave broke on top of me, leaving a great big crease through the bottom."