Thieves were waiting to pounce when Brisbane yachtie Trevor Hill sailed in to Port Taranaki on Monday for the 2010 solo Tasman yacht race.
Hill, 34, arrived about 4.30pm and after clearing Customs, he and crewmates Trent Latter and Hugh Bekkers went ashore from his 12m sloop Apriori in their dinghy for a meal.
When they returned someone had stolen the outboard motor and a safety harness from the dinghy.
"It's pretty disappointing as I had borrowed the motor and just spent a heap doing it up," Hill told the Taranaki Daily News.
"Now I'll have to replace it with a new one."
The harness, which doubled as a life jacket, contained an emergency locator beacon, a strobe light and a knife.
The thieves had set off the beacon and the signal was picked up in Australia.
The combined value of the stolen gear was about $2200.
Hill was the first to arrive for the event which starts on April 4.
The chairman of the race organising committee, Ron Scott, said the theft was a "bad look" for New Plymouth.
