It’s cold, pretty close to frigid on the shore of Sengekontacket Pond. It’s cloudy, pretty close to dark. The sky is threatening rain, and the wind is gusting well above 20 miles per hour.

Perfect.

This is the kind of weather kite sailors Rob Douglas and Alex Caizergues live for.

The friendly rivals are competing in the North American Speed Sailing Invitational on Martha’s Vineyard this month. The competition began Oct. 17, and runs to Oct. 31.

Lynch and Associates, a financial firm owned by seasonal Edgartown resident and kite boarding enthusiast Bill Lynch, sponsored the tournament and put up $25,000 in prize money. Competitors take as many runs as they can in an hour over a 500-meter course, averaging their two best times. Depending on the wind direction, they sail in Katama Bay, off Joseph A. Sylvia State Beach, and off Cape Pogue, in addition to Sengekontacket Pond.

Competitors rip along Vineyard shores at astounding speeds. They skim over the water on a tiny board, hitched to nine square meters of kite gliding 100 feet high by nearly invisible Kevlar lines. If they were driving cars, they would be breaking the speed limit on nearby Beach Road.

Rob Douglas has often held the title of fastest man on the water. — Mark Alan Lovewell

On a recent afternoon, Mr. Caizergues gripes about the plunging temperature, as his team makes final adjustments on his kite board for the second race of the day. He wears a black helmet with so many dings and scratches, it looks like the remnant of a motorcycle accident. Under his wetsuit is a set of body armor, to protect him from injury.

Up on Beach Road, Mr. Douglas needs help with an injury suffered in competition a week earlier. A very nasty cut on the top of his foot required 13 stitches. It’s not healing well. Perhaps the fact that his assistant is covering the small bandage with several wraps of duct tape so he can race today has something to do with the pace of recovery.

These guys are tough.

Over the past seven years, Mr. Douglas and Mr. Caizergues have swapped the world kite sailing speed record back and forth.

“It’s a great, healthy rivalry,” says Mr. Douglas, who is general manager of The Black Dog. “We’ve gone back and forth. We’ve been competing since 2008.”

Currently Alex Caizergues holds the title of fastest man with a speed of 65.16 miles per hour. — Mark Alan Lovewell

Mr. Caizergues grabbed the record in 2007, sailing an average speed of 55.14 miles per hour over a short course in Lüderitz, Namibia.

Mr. Douglas took the title in September 2008, sailing at 57.35 miles per hour, only to lose the honor to Mr. Caizergues a month later, when he recorded a run of 58.19 miles per hour.

In 2009 and again in 2010 Mr. Caizergues broke his own records, but at the end of the 2010 competition, Mr. Douglas claimed the title of world’s fastest sailor, with a record run of 64.04 miles per hour. At the time, it was the fastest anyone, in any kind of vessel or on any kind of board, had sailed under wind power alone.

That record stood for three years, until Mr. Caizergues set the current record at 65.16 miles per hour in 2013.

The records are certified by the World Speed Sailing Record Council, and timed with precise GPS units worn by the sailors during competition.

There will be no records set on Martha’s Vineyard. Perfect conditions are necessary for 65-mile-per-hour-plus runs. The water here is a little too choppy, and the wind is usually a little less than record-setting strength.

But even at slightly slower speeds, the competition is blazing fast. In order for a race to be certified, the wind has to average 16 knots or higher. At that speed, most conventional sailors are reefing sails or heading back to port.

At this level, everyone is good, and everyone is fast. Winning means sailing right on the edge of control, with the board barely touching the water, and a wreck just a sudden wind gust away. Many times, the winner in kite sailing is the one who makes the right decisions.

“The equipment has been fine tuned,” Mr. Douglas says. “It comes down to picking the right equipment, making a decision on the kite size, the board, the fins. That’s what it takes to win races and to go fast.”

Sengekontacket Pond is popular place for kite sailing. — Timothy Johnson

Through Oct. 28, with 10 races complete in the current competition, Mr. Douglas is putting home field advantage to good use, leading the field by a wide margin. He placed first in seven of the 10 races. He holds the fastest single run time at 53.62 miles per hour.

Mr. Caizergues has the second fastest run, just a fraction of a heartbeat slower at 53.53 miles per hour, but he was fifth on average times after 10 races.

Both men will continue their quest for speed. Mr. Caizergues will make another record attempt this next month in Salin-de-Giraud, near his home in the south of France. He has invited Mr. Douglas to compete.

“He invites me to his home, I invite him to my home,” Mr. Douglas says. “We have a great friendship.”

The day’s racing is done. Mr. Caizergues pushed his equipment beyond the limit, managing to break off a piece of his board and put a few more scratches on his helmet.

Mr. Douglas leans on a friend, hobbling in pain back to his van, where he rips off the duct tape, and puts a new bandage on his injured foot, still shriveled from cold salt water.

That nasty cut didn’t heal much on this day. But he went fast. Fastest of all.