She will attempt to "zorb" her way from the beach at Donaghadee to Portpatrick harbour in Galloway for Sport Relief.
The challenge would be a first if she manages to complete the lengthy crossing.
It has been estimated it could take her up to 14 hours to cross the 20 miles (32km) of open water.
Lindsey has been training with Prof Greg Whyte, who prepared Davina McCall and David Walliams for their Sport Relief challenges.
"The most daunting part of this challenge has always been how heavily we are relying on the weather," she said.
"I've been training for months for what will be the biggest and best challenge of my life, but I don't think anything can prepare me for what the Irish Sea has in store.
"Something I do know is that I'll give it everything I've got - I am so determined to make it to Scotland and I hope it inspires everyone watching to get up and get involved with Sport Relief this year."
Prof Whyte described it as an "incredibly tough" solo challenge.
"The unique adventure that Lindsey is about to embark upon holds a host of physical, psychological, nutritional, tactical and technical challenges," he said.
"In addition, factors beyond Lindsey's control, including the weather, will play a crucial part in Lindsey's success.
"This is an extraordinary challenge which will require an extraordinary performance from Lindsey to achieve success."
She will head to Northern Ireland for final preparations for the crossing attempt later this month.
Viewers can follow Lindsey's progress from 26 February every Thursday on Blue Peter on the CBBC channel, with The Wave Runner challenge airing on 17 March.
Blue Peter presenter Lindsey Russell is to try to cross the sea between Northern Ireland and Scotland later this month in a giant inflatable ball.