The Old Port Half Marathon, held last Sunday, has seen impressive growth in its four summers of existence. This year, 2,448 runners finished what has become one of the state’s biggest races, second only to the Beach to Beacon 10K (6,247 finishers last August). It has become Maine’s largest half marathon (the Maine Half Marathon had 1,974 finishers last October).

The Old Port Half is part of a two-day, Portland waterfront event (Shipyard Brewing Co. Old Port Half Marathon & 5K & Summer Festival) with music, food and such on Saturday, and races and more on Sunday. The 5K has boomed, too, with 759 finishers this year. Overall, the combined numbers have ascended from 1,000 to 1,500 to 3,000 to 4,000 registrants.

But the half marathon has seen its share of organizational problems over the years. More than its share, actually.

The course, changed slightly from last year, starts and finishes at Ocean Gateway on the city’s eastern waterfront. At about the 3.25-mile mark, on the Western Prom, there is a right turn off West Street and onto Vaughn. But a volunteer flagger at the intersection did not direct the lead runners to turn, and the cyclist who was the “lead car,” so to speak, kept going straight on West Street, so the runners naturally followed him.

By a piece of amazing good luck, and possibly some directional awareness on the part of the cyclist, about a quarter-mile farther on he did bear rightish, onto Clark Street, and led the runners about half a mile to the intersection at Danforth Street – and back onto the course.

But the damage was done. The detour shortened the 13.1-mile race to just under 12.8 miles for the hundreds of runners who took it.

Their total number has yet to be determined, race director Erik Boucher said Thursday. He said he was told by the 457th finisher that she ran the short course, and he knew the 625th finisher ran the full course, so the wrong-way contingent numbers somewhere in between.

Boucher explained that the course error was spotted by Portland recreation department official Ted Musgrave, who was a couple blocks away down Vaughn Street where the runners were supposed to go and was able to alert race officials in time for most of the field to be directed the right way.

The finish times stood for all. (Consider the potential headaches of sorting the awards. Just as well the race awards are custom buoys, not cash prizes.)

On the race’s Facebook page, commentary is lively, much of it from forgiving runners praising the race (“Honest mistake and hats off to you for owning up to it”) after Boucher posted an apology Tuesday and an explanation of the mistake, and wrote of plans to prevent the same happening again next year.

He also apologized “for the way I handled this yesterday,” in responding to “the assaults of negative posts” in a post that since has been removed. In a screen-shot fragment copied from that thread, an angry short-courser is informed “I would be grateful if you didn’t run this race again. The sport needs less whiners.”

It has to be said, the event has given people something to whine about. Last year the 5K saw an awkward bottleneck when runners had to wait to ascend stairs early in the race; and on that hot summer day the last two water stations in the half marathon ran out of water, a factor in five people requiring hospital treatment.

In 2012, on a different course that took runners to Falmouth via Tukey’s Bridge, the entire women’s first wave (there were two waves) somehow ran not on the bridge’s sidewalk but were allowed to follow the lead car onto the ramp and actually run on I-295; luckily, inside road construction cones in place. (This, too, shortened that course.)

Boucher, who as GiddyUp Productions LLC owns the races as well as directing them, does not shy away from discussing problems. For example, he calls the stairs 5K “a stupid course design” that backfired when so many runners entered. Of the half marathon water crisis, he says he failed people and noted the city wouldn’t allow the race to be held this year unless he proved to emergency personnel that the crisis would not recur.

He is offering a 2015 entry-fee discount (yet to be determined but probably $20 or $25) to 2014 short-course runners. As for a refund for this year’s race? “People haven’t really asked so it’s not clear what they want.”

That 2015 event may see different courses; Commercial Street and Ocean Gateway are due for reconstruction. But Boucher sounds determined to see the races thrive.

He added, “I’m grateful people come back.” (It’s worth noting that 59 percent of this year’s entrants were from out of state.)

“I’m trying to be honest and transparent,” Boucher said, “and I think because of that, people have faith that I am working things out.”

John Rolfe writes about road racing for the Maine Sunday Telegram. He can be contacted at 791-6429 or at:

jrolfe@pressherald.com