Away they go with just the small matter of 3,000 miles of rowing the Atlantic to go.
Military personnel and veterans are among the teams setting off on the 'world's toughest row' – the Talisker Whisky Atlantic Challenge.
A record number of entrants must now battle sleep deprivation, hallucinations and hunger, all with the same objective – to take on the unique experience of crossing an ocean in a rowing boat.
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- Final countdown: Behind the scenes in preparation for the 'world's toughest row'
Families, friends and local spectators gathered on the jetty at San Sebastian in La Gomera, Canary Islands, to wish them good luck and farewell.
The next time they will be seeing them is in more than a month's time at Nelson's Dockyard English Harbour, in Antigua and Barbuda.
Royal Navy submariner Lieutenant Commander Callum Fraser from Team HMS Oardacious was joined by his wife on the jetty and said he was "really excited" to just get going with the challenge.
"We've been ready to go for, like, four days, the conditions aren't perfect but that's a great thing for us, it means we can really fight into the conditions and try and get ourselves ahead of possibly the other crews," he said.
His wife, Sophie, is "very, very proud" and is especially excited to be able to track him and the team's progress on an app.
The submariner also told Forces News, as he showed off his bracelet made by his daughter, that he has been given quite an extensive list of sights to spot for the children before he gets to the finish line, including a shark and whales.
"Yeah, she wants me to bring home a shark, she wants me to swim with dolphins, make sure I see some videos of whales," Lt Cdr Callum Fraser said.
But is he confident about completing his daughter's to-do list?
He said: "Not in the slightest. I will manage expectations as I go, I will tell them I've seen stuff but they were too quick."
The HMS Oardacious has already sent its first video back from the ocean.
Lieutenant Tom Hutchinson said in the message: "Eighteen months of training for today, today's the day."
The team also sent "lots of love, and we'll see you soon".
This year, there are more teams than ever before: 43 crews, 127 rowers from 17 countries with a huge proportion of them from the military.
The importance of mental mindfulness has been stressed by a lot of the crews as a way of getting them through the challenge.
Not only will they be battling the elements at sea but, with the challenge continuing through until the middle of January, it will mean Christmas festivities will have to be celebrated away from their families.
Lieutenant Max Lawrence, of Team Atlantic Guardsmen, told Forces News in the video how he will keep the festive spirits up during the gruelling row.
They shared a unique technique the team will be using to help when they are out at sea.
"We have a codeword which is 'TM', which stands for too much. Which means that at the moment you say TM it's not what you are saying, it's how I'm currently receiving it.
"It's something you can't measure... TM just means 'stop saying what you are saying, back off, reset the conversation and go back to it in a different way or when the person is ready to receive what you are saying'."