Home clubs Property Brokers United and Wanganui Vet Services Marist will host Levin Old Boys and Weraroa CC respectively in their first games at 12 noon, before coming back at 3.30pm to play the second round with association derby fixtures.
These four sides make up Pool 1 of the competition, with Pool 2 consisting of Horowhenua's Paraparaumu Medical Centre CC and Kapiti Old Boys, along with Wairarapa's United CC and Burger King Red Star CC.
Pools 1 and 2 will play a third round of games on October 23, with the top sides from each pool then going on to contest the final at a later date.
November 6 will be the start of the Coastal Challenge two-day competition, with the second day of the four opening-round matches set for November 20
Round 2 will be December 4-18, with the final for the two remaining undefeated teams being played over the full weekend of January 8-9.
The original 50-over Coastal Challenge Cup will start in the New Year, with round one on January 29, carrying on through to the finals on March 26.
Dividing the season into specific tournaments presents both United and Marist with unique opportunities for Coastal Challenge success.
Marist won the 50-over title in 2018-19, while United have played in four finals, a record they share with Paraparaumu, but have yet to claim the title.
Follow results and draws for the tournaments at https://www.crichq.com/competitions/7265/draws/current
Draw for October 16, Coastal Challenge Cup Twenty20
Pool 1, Tasman Tanning Park
12 noon: Wanganui United vs Levin Old Boys; Wanganui Marist vs Weraroa CC.
3.30pm: United vs Marist; Levin vs Weraroa.
Pool 2, Park Sports Ground and Wairarapa College, Masterton
12 noon: United CC vs Kapiti Old Boys; Red Star vs Paraparaumu CC.
3.30pm: United vs Paraparaumu; Red Star vs Kapiti.
Previous Coastal Challenge Cup winners (50-over format)
2015-16: Tech Old Boys (Wanganui); Runnerup: Levin Old Boys
2016-17: Paraparaumu CC; Runnerup: Wanganui United
2017-18: Paraparaumu CC; Runnerup: Wanganui United
2018-19: Wanganui Marist; Runnerup: Paraparaumu CC
2019-20: Levin Old Boys; Runnerup: Wanganui United
2020-21: Paraparaumu CC; Runnerup: Wanganui United