An Aquahawk for 10 years, Dyer, has won gold and silver medals in 400 metre individual medley races at national age group championships in the past. He will be hoping for similar success at this year's nationals which start in Wellington on April15.
Before then he will have the Central Long Course championships next weekend and the March 11-13 national surf lifesaving championships in Ohope where he will represent the Ocean Beach Kiwi club.
Sixteen-year-old Year 12 student Madams finished second to Bassett-Foss in last year's 2.5km race. Today will be his fourth outing in the race.
"Last year I spent too much time focusing on Bertie instead of the buoys," he recalled with a laugh.
A specialist long distance swimmer, Madams, is getting back into the competitive scene again after taking a break last year to concentrate on his academic pursuits. His next appearance at nationals level will be the August short course championships. He pointed out his team will also do the 300m individual and team events as a warmup for the 2.5km race with the aim of winning prizes for their school.
Wills, who like Dyer and Madams is coached by Frank Wylie, will be tackling his third Ocean Swim.
The Westshore Surf Life Saving Club member finished second to Dyer in the under-16 surf race three weeks ago.
"I pushed him hard all the way. That's the way we should approach this weekend's race too ... chase Hadlee and if keep on each other's feet we should do well in the teams race."
Another Year 12 16-year-old, Wills, is in his first year back in competitive swimming after taking a break.
Another Aquahawk, Ruby Adsett, is the favourite for the women's 2.5km individual title. She also completed the under-16, 19 and open treble at the Hawke's Bay surf life saving championships.
More than 220 starters across all the divisions are expected.
It has been staged today with the aim of attracting swimmers from out of the Bay who may be attending the Art Deco festivities.