You can't fault German scullers Eric Knittel and Stephan Krueger for their speed out of the blocks.

The duo started rowing together in the double in April last year. Within six months they were world champions.

The Germans have high expectations at Lake Karapiro next week. They are among the powerhouses of world rowing; Knittel and Krueger, through their deeds last year, will be among those of whom expectations will be high in the German camp.

They came together from different directions.

Stroke Krueger, a 21-year-old from Rostock in the northeast of the country, was in the German quad which finished sixth in the Beijing Olympics in 2008, having won silver and bronze medals at the world junior championships of 2005 and 2006, and gold in the quad at the world under 23 champs in 2007.

Berliner Knittel, 27, began as a lightweight and won two silvers and a bronze in a mix of crews at three successive world under-23 championships from 2003.

Knittel struggled with health issues in 2008 but once they were paired together last year they hit the water with a splash.

Wins in the Munich and Lucerne World Cup regattas were followed by completing the hat-trick at the world title in Poznan, Poland, in August last year. But it was a tight squeeze for Krueger and Knittel. They won in 6min 07.02s, shading the formidable French pair Julien Bahain and Cedric Berrest by 0.80s.

New Zealand had a strong interest in that final too, with Nathan Cohen and Matthew Trott finishing fourth.

Cohen is now teamed with former world under-23 champion Joseph Sullivan and they will expect to be at the business end of the final next weekend.

That gold was one of three victories for the German squad, the others coming in the men's eight and the lightweight men's coxless four.

This hasn't been a smooth year for the German double.

"We have had some problems in our season," Krueger said.

"In the first period I had been unwell with my shoulder then Eric got ill and we had to recover again.

"I think we have reached the point where we feel comfortable and powerful again - nearly like last year."

Which sounds a vaguely ominous warning for their rivals.

The men have done their homework too.

They were part of a small German contingent which took the trouble to come to Lake Karapiro last February for the national championships.

It was a fact-finding trip, aimed at getting a feel for the location, checking out the course and to give themselves every chance of repeating their success at Poznan.

Knittel suffered a bout of sickness this year. After racing in the semifinal of the Lucerne regatta in July, they withdrew as the bowman battled an illness which had them baffled.

Ordinarily the timing might have cost them their world championship campaign. However, with the championships in New Zealand for only the second time - and the first for 32 years - that meant the international season was extended past its usual finishing point around August-September.

"So we had time to find our form again. Since Lucerne many weeks have passed and that's helped us," Krueger said.

So what about their prospects? There are French, British and Estonian rivals with decent credentials, not to forget Cohen and Sullivan, who were third in the Lucerne final, 1.66s behind Bahain and Berrest. "I think there is a chance to defend our title," Krueger said.

"But the double is a class which is quite difficult.

"The competitors are strong so it's a great challenge."

Germany's overall progress at the worlds will be worth watching.

Last year, they and New Zealand won most golds across all classes, four apiece, one ahead of Britain, the United States and Ukraine. Germany and Britain finished top on all medals, with nine each.