This year is the series' 10th anniversary.
Wilkinson, who was diagnosed with Parkinson's 12 months ago, swims in the 75-year age group.
"Just lining up is a challenge for me these days.
"I'll probably do less next year and this (this weekend's race) could be my swansong," he said.
Although depending on how his body holds up, he is keen to compete at the World Masters' Games in Auckland next year.
Born and bred in Kaitaia, the former painting contractor started frolicking in his home town's swimming pool at the age of 16.
But it wasn't until a group of swimmers came up from Auckland in the late 1950s that he became serious about the sport.
"In those days, we were part of Auckland centre.
"I won the 50m freestyle and was then headhunted to Auckland to train with professional coach Paul Kraus."
Wilkinson won selection in the Auckland swimming team and went to the national finals in Blenheim in 1960 where he won a gold in the 4 x 50m relay.
About 15 years ago, he brought a haul of one silver and three bronze medals from the World Masters' Games in Melbourne.
There has been no let up in the preparation for today's race and Wilkinson hopes fellow Whangarei swimmer Pat Bohne from McLeod Bay takes out the women's category.
The beauty of the Ocean Swim series is anyone can train and turn up, whereas in the past swimmers had to be registered with a club to compete.
Wilkinson's badly scraped leg was wrapped up early this week but the injury shouldn't slow him down today.
Looking back, he has no regrets.
"It's been a great career for a middle of the road swimmer. I've swum with the best locals and the best in the world. What else can I ask for?"
