Ireland’s Eoin Rheinisch has qualified for the semi-finals of the K1 canoe slalom.

Although Rheinisch ended up in 12th place of the 15 kayakers who made it to the semi at Lee Valley, his place was virtually assured following the first of the two runs after he placed sixth of the 22 competitors in 89.97 seconds.

He clocked 90.72 for his second run and will have been encouraged by not incurring a single time penalty in either run.

Germany's Hannes Aigner was well ahead of the rest of the field.

His second run of 83.49 seconds was 3.58 seconds faster than Spain's Samuel Hernanz's best effort.

Meanwhile, canoe slalom chiefs were forced to defend their course design after concerns that it is too tough for right-handed paddlers.

Gate 12 seemed to annoy some of the athletes, including the Frenchman and former Olympic champion Tony Estanguet, who said it unfairly penalised canoeists who were right-handed.

Canoe slalom courses are set by a series of gates which need to be negotiated. Some gates are green and can be approached head-on but red gates must be negotiated in reverse, often against the flow of the water.

Gate 12 was red and some felt it should have been green.

Estanguet, 34, who won gold in both Sydney and Athens, said: "I think it's a strange course. It's hard to understand why they put this kind of gate (gate 12) because it's not really good. Depending on the water you had, sometimes it was possible to go and other times it was impossible.

"I have some problems to understand the objective of the designer."

Thomas Schmidt, who set the course, said it will get even trickier for the canoeists later in the week for the semi-finals and finals.

He said: "The course should be so everyone can perform at their best level and the main attractions for the spectators are in the middle of the course because that is where the biggest crowds are.

"I think the balance of the course was quite good. We will make it harder and a little bit trickier. The (underwater) obstacles were set in February and haven't been changed since but we can do a lot with the gates."

But other canoeists were more supportive of the course. The Czech paddler Stanislav Jezek described the £35million course as a "paddler's paradise", telling reporters that as a left-handed canoeist he had no objections about gate 12.

He said: "It's absolutely clean water and the course is very good. I think all of us want to paddle here."

Estanguet still qualified comfortably for Wednesday's semi-final, finishing seventh with a time of 93.24.

The C1 category heat was won by Beijing gold medallist Michal Martikan.

The 33-year-old, from Slovakia, left it all to do in his second heat after missing a gate in his first run.

But he secured a near perfect run of 90.56 seconds to secure first place, ahead of the young Slovenian paddler Benjamin Savsek, who set an early pace in his first run.