"It's something we're pretty passionate about," he said.
"It's not the nicest disease. It takes too many people."
Although there is no cure yet the research being done by the New Zealand Breast Cancer Foundation was helping patients and their families, Craig said.
Raewyn said when she received an email from the foundation about a year ago asking if she wanted to take part in the trek it felt like a perfect opportunity.
The family had lost loved ones to breast cancer so they wanted to help such a good cause and going to the Great Wall of China had always been on Raewyn's bucket list.
"The Breast Cancer Foundation is doing some great work ... trying to get it detected early so no one dies from it," she said.
"The trek is about raising money and raising awareness.
"Once we start the walk we can just enjoy it and think about those we've lost ... the walk will be the emotional side of it."
They would not have been able to do it without the support of friends, family, local businesses and work colleagues for all the times they've "skived off work to train".
"The Hawke's Bay community rocks."
The pair have been training by doing walks around Hawke's Bay almost every week for the past year and have seen some of the best scenery in the region, she said.
The group will leave New Zealand on Thursday for the 10-day Pink Ribbon Trek 2018, run by Inspired Adventures, which includes five days walking 10-15km sections of the wall.
The couple have extended their trip to include a stop in Vietnam and a brief stint in Abu Dhabi to visit Raewyn's brother.
They have also started a Facebook Page Findlay's Great Wall Fight against Breast Cancer to document their journey.
Another trek, with about 15 other New Zealanders, will take place straight after.
The two groups have raised more than $134,000 for the New Zealand Breast Cancer Foundation between them.
The money will go towards research as well as providing practical support to New Zealanders with breast cancer such as childcare during patient appointments, lymphatic massages to reduce pain and swelling, physical rehabilitation sessions and home care for patients.
Donations to the cause can be made through Craig and Raewyn Findlay's page.