Imagine sleeping for two hours and then waking again for two repeatedly for up to 45 days.
Now think about rowing across the Atlantic with no bathroom facilities and limited cooking ability in those two waking hours.
That is the challenge that six women are embarking on when they attempt to row 3,000 miles unaided across the Atlantic Ocean.
They will be the first female crew to make the journey which begins in La Gomera in the Canary Islands and will finish in Barbados.
Kate Richardson from Portadown is one of those making the journey which hopes to raise £1m to help human trafficking victims.
The money will go towards ECPAT UK and the A21 Campaign, both of which Kate said "work tirelessly against human trafficking".
No rowing experience
The 22 year old joins five other women women - Julia Immonen, Andrea Quigley, Debbie Beadle, Helen Leigh and Katie Pattison-Hart.
Kate, the only team member from Northern Ireland, met Row for Freedom founder Julia Immonen through mutual friends and agreed to take part despite having no rowing experience.
"I said yes to this challenge before I even knew how to row," she said.
She has been training for often four hours a day, sometimes during the night to acclimatise herself to the rota pattern.
"It's always going to be two hours on and two hours off so we are always going to be battling sleep deprivation," she said.
"That's just something we have to get used to.
"It's amazing how your body adapts and your body does eventually get used to it and you learn to just be able to sleep as quick as you can when you do have two hours rest."
Kate will meet the rest of the team in Tenerife on Saturday, before getting a boat to the starting destination of La Gomera.
"In this time we have to prepare 60 days worth of food, get our medical list sorted and check all the electronics on the boat," she added.
The race itself starts in early December to coincide with the end of the hurricane season and to get the most benefit from the easterly trade winds and Atlantic currents.
As well as a lack of sleep, the women will have to live on a diet consisting of high-calorie expedition foods and desalinated water.
As far as challenges go, this certainly will be a test of endurance.
According to the team's website: "More people have gone into space or climbed Everest than have rowed an ocean."