With 40 mph winds whistling around him, the New Zealander was being dragged through the most remote waters on the planet, 1,000 kilometers from the nearest coastline.
After an attempt to fix his vessel's mast had gone disastrously wrong, Colman had slipped from the boom, slamming overboard and falling into the rough seas.
Already haunted by the death of his father in a sailing accident, Colman was forced to confront his own mortality during the Vendee Globe -- a non-stop, 28,000-mile, solo sailing race.
"My father was killed in an accident on a boat," Colman told CNN's Mainsail. "In my first race around the world, I lost my crew member and it took 30 minutes of searching in bad conditions to get him back.
"It was very tough for me to be on the receiving end of that. To find myself helpless in the water."
Colman was able to scramble back aboard thanks to a leash that kept him tethered to the boat. He recovered to eventually reach the finish line in the French port of Les Sables d'Olonne on Friday, February 24.
He had been at sea for 110 days and finished the race in 16th place, over 35 days behind winner Armel le Cleac'h.
Despite being in regular contact with his wife Clara, Colman kept his brush with disaster a secret until he was back on dry land.
"My mother is a widow of the sea and my wife is already afraid of what I go through everyday," explained Colman, who reached the end of the race despite his boat "Foresight Natural Energy" being dismasted.
"In many ways she has slept less, or with more stress, than I have these past months. I didn't see the need to add to their suffering, collectively. It was something that I had to keep bottled up inside me."
Food and Photography
One welcome distraction for Colman was photography.
Using his own drone, he was able to capture stunning images of life on the high seas.
Through regular podcasts and video diaries, he was also able to showcase some of the lighter moments of his voyage, such as making a salad.
To supplement his diet of army-style dehydrated food, Colman grew alfalfa and mustard seeds which offered a welcome change from packet meals.
Colman needed all of the energy he could muster to wage a continuous battle against the elements. Not to mention an onboard electrical fire and the running repairs needed to keep his boat afloat.
"It feels like I went through a war but in three months," added Colman. "It's not possible to do that without being changed.
"It's always very humbling to go and get a good thrashing and to be reminded who's boss and to realize that you can't fight against the Southern Ocean and you have to work with it.
"There are many, many forces outside of our control and the only thing that you can change is your own mindset."
To hear more from Colman, watch March's edition of Mainsail, which airs on CNN International Mar 4: 1730 (GMT); Mar 5: 0730, 2230; Mar 9: 1030, 1730; Mar 11: 0730, 2230; Mar 12: 1630.