The national championships will be the first of several domestic events where Kiwi surfers get the opportunity to push for selection in the New Zealand team to attend the World Surfing Games in May.
Under International Surfing Association (ISA) guidelines, Stairmand and Williams, along with Paige Hareb (Taranaki) and Ricardo Christie (Mahia-Gisborne) are automatic selections for the New Zealand team, leaving only one spot each for the men and women.
New Zealand will push for a further two athletes at the World Surfing Games, with the top five unqualified males and seven unqualified females at the event filling up the remaining athlete quota of 20 in each division.
Next week's competition will be the 12th time the national championships have been held in the South Island, and the eighth time Dunedin has hosted the event.
The Otago coastline offers the type of wave-rich stretch of New Zealand that is required to host the six-day event.
Raglan's Point Boardriders will go into the event as the top club after a stellar run of results in 2019. They will be favoured to take the title again in 2020.
Hosts South Coast Boardriders of Dunedin will be a big force with a large number of members taking part.
Traditional strongholds such as Gisborne and New Plymouth boardriders could be in the mix, too.
Also up for grabs next week will be the Peter Byers Overall Performance of the Event Award.
The longest running surfing event in New Zealand, the national championships will take place over six days from Monday to Saturday.
In the 56-year history of the event, the national championships have grown to encompass 29 divisions spread across all disciplines and age groups.
Over 250 entries are expected. Recent additions include divisions for under-14 boys and girls, over-60 males and females, and longboard, stand-up paddleboard, bodyboard and kneeboard disciplines.
Heats will run from about 8am to 4pm daily, with the primary venue being St Clair Beach. If conditions permit, the event could go mobile.
2015: Billy Stairmand (Rag). 2016: Billy Stairmand (Rag). 2017: Billy Stairmand (Rag). 2018: Ricardo Christie (Gis). 2019: Billy Stairmand (Rag).
2015: Gabriella Sansom (Auck). 2016: Ella Williams (WGM). 2017: Ella Williams (WGM). 2018: Raiha Ensor (Mnt). 2019: Aimee Brown (Gt Barrier).
2015: Kehu Butler (Mnt). 2016: Elliot Brown (Dun). 2017: Jonas Tawharu (Mnt). 2018: Conor McLennan (Chch). 2019: Caleb Cutmore (Rag).
2015: Kea Smith (Mnt). 2016: Elin Tawharu (Mnt). 2017: Saffi Vette (Gis). 2018: Elin Tawharu (Mnt). 2019: Saffi Vette (Gis).
2015: Thomas Kibblewhite (Auck). 2016: Zen Wallis (Piha). 2017: Thomas Kibblewhite (Auck). 2018: Zen Wallis (Piha). 2019: Jamie Andrews (Tara).