Van Dyk, who weighs 82kg, is the most capped international netball player of all time - with 145 games for the Silver Ferns and 72 for South Africa.
She is a former New Zealand Sportswoman of the Year, Netball World Champion and Commonwealth Games gold medallist.
Ms Sommerville said she was motivated by the idea of raising money for those who cared for her father, Greg.
He was diagnosed with lung cancer in 2009 and was given just months to live.
Ms Sommerville's aunt and two uncles also died from the disease, as did her father's best friend.
"I am doing this to give something back to Hospice after what they did for my father."
Last year, $100,000 was raised for Hospice Waikato at the Fight for Life.
Hospice Waikato is again the Fight for Life charity in 2015 with Duco Events pledging at least another $100,000 this year.
The fight night will be headlined by Joseph Parker.
Troubled rugby player Zac Guildford will also take on Art Green, star of The Bachelor NZ.