Fifteen-year-old Samuel Kahn is devouring the fleet at the Bell Mumm 30 World Championship in Toronto.

Kahn, aka Shark, and his world-class crew of Mumm 30 neophytes finished third, first and second in Wednesday’s second day of racing – Lewmar Day around the historic Royal Canadian Yacht Club – to seize a six-point lead after six of 11 races.

“Awesome stuff,” said a rival, Richard Perini of Sydney, Australia, who had a fair day himself by wrapping a second and first around a 17th to climb into fifth place in the feisty 21-boat fleet.

The younger Kahn took over the lead from his father Philippe, the California software developer who opened the day with a win, followed by a fifth and a wind-dying 19th, settling into third place 11 points off his son’s pace and five points behind second-place Fred Sheratt, the local hope from the host club.

The Shark’s stunning performance is an even larger surprise than the weather. On the first day of autumn, when the resident Canada geese should be flying south and citizens donning winter woolies, the region remained in the grip of a high-pressure system with a peak temperature Wednesday of 29C – probably warmer than it was in the Kahns’ second home in Hawaii.

The conditions meant light to moderate winds fading to very light and swinging 45 degrees left through the afternoon.

“It was hot,” Kahn said – his only complaint. When he and several of the same crew won the Melges 24 worlds last year a fair share of credit was given to the other guys in the boat, particularly professionals Richard Clarke and Mark (Crusty) Christensen. But when a quiet lad of 14 and now 15 steps into an authentic international one-design class like the Melges 24s and Mumm 30s and outperforms veterans as Kahn is doing, some extraordinary forces must be at work.

At least he raced the Melges 24 a couple of years before reaching the top. Here, he and each of his six crew members are racing a Mumm 30 for the first time in their lives.

Clarke, the tactician, said: “His improvement over a year is just amazing. He’s giving us a little feedback now. He used to be a mute back there, but now when we’re sailing a target speed of 6.2 knots he says, ‘I could be going 6.3; the windward telltales aren’t flowing.’ ”

Clarke also notes Christensen’s contribution for “setting the boat up so well” by tuning the rig and trimming the sails.

Christensen said: “None of us has ever raced a Mumm 30 before this week, so we’re all still learning. Shark has always listened and done everything we said, but now he’s saying how it feels. The nice thing is he’s really unfazed by it all.”

The unassuming skipper said: “Mainly, if I give any feedback it’s to see if I’m doing the right thing. Pretty much all I do is look at the telltales and the speedo.”

But he’s also having fun. “Light air is all about concentration,” he said, showing a subtle sense of humour. “I had an extra cup of coffee this morning that may have helped.”

Standings (after 6 of 11 races)

1. Pegasus 20, Samuel Kahn, Honolulu, 3-1-17-3-1-2, 27 points

2. Steadfast, Fred Sheratt, Toronto, 8-2-4-6-2-11, 33

3. Pegasus 591, Philippe Kahn, Honolulu, 5-3-5-1-5-9, 38

4. Tramp, Tom Ritter, Bloomfield Hills, Mich., 1-7-7-15-4-5, 29

5. Foreign Affair, Richard Perini, Sydney, Australia, 2-12-13-2-17-1, 47

6. Team Intermac, Dan Cheresh, Holland, Mich., 6-10-9-10-7-6, 48

7. Cygnet, Richard Swann, Fairfield, Conn., 13-8-1-12-10-8, 52

8. TeamBOLD, Nelson Stephenson, Southport, Conn., 15-11-14-9-3-4, 56

9. Groovederci, Deneen Demourkas, Santa Barbara, Calif., 4-18-2-14-6-14, 58

10. Calvi, Carlo Alberini, Pesaro, Italy, 16-5-11-7-13-7, 59

11. Team Traffic, Philip Werheim, USA, 14-13-21-4-9-3, 64

12. USA 65, David Pyles, Easton, Md., 7-16-6-18-8-10, 65

13. Three Niner, David Gonzalez, Lambertville, Mich., 12-15-10-5-11-13, 66

14. Notorious, Kevin Brown, Toronto, 9-9-12-8-16-16, 70

15. it, Jim Sminchak, Euclid, Ohio, 11-4-16-16-18-15, 80