The multi-talented Year 13 pupil is part of the Curtis Wooten-coached HBHS basketball team competing in the three-day annual high school Super 8 tournament in Napier from Monday.
The 18-year-old point guard has flourished in the game, earning bench status with the IMS Payroll Hawks team this winter.
Marsh will play alongside New Zealand age-group guard Isaia Jones-Mitchell in the Caleb Edwards-captained host team.
HBHS are in the hunt for another bragging rights in Hawke's Bay, after securing their last title in 2013 when the school also were hosts.
However, Wooten's boys have been bridesmaids more often than they'd like to be reminded - five in a row although they have clinched an impressive six crowns in the history of the tourney.
New Plymouth Boys' High School (NPBHS) are only a couple behind in a tourney that includes Napier Boys' High, Palmerston North Boys' High, Rotorua Boys' High, Hamilton Boys' High, Gisborne Boys' High and Tauranga Boys' High split in two pools.
HBHS are in pool B with NBHS, PNBHS and Gisborne at the Pettigrew-Green Arena, Taradale.
NBHS will have fellow Hawks bench "tweener" (big guard/small forward) Wilfred Dickson in their squad.
Wooten says PNBHS and Rotorua have two age-group national reps and Hamilton one so the tourney won't be shy of pedigree players.
Unlike many high-schoolers, Marsh has "no interest" in going on overseas scholarships.
"I want to finish my UE [University Entrance] and go to university in Auckland or Massey to become a PE teacher or something to do with sport."
Equally adept at rugby and touch in summer, Marsh's partiality towards basketball came at Hastings Intermediate when a cousin, Ashton Robinson, invited him to training.
"The coach, Jason Williams, liked what he saw, I guess, so that year we went to the Aims tournament and won the basketball title," says the teenager of the annual intermediate schools Mecca at Tauranga.
His choice was easy for a code that appeals because of its licence to run, jump and pass on polished courts.
"I didn't have to be too big for rugby. As a junior I couldn't make the fifteen that year."
Inspiration to excel in sport has never been an issue for the schoolboy.
Tall Black Everard Bartlett is a relation and Melbourne Storm centre Tohu Harris is his mother's first cousin.
Former Magpie and ex-NZ touch rep Nui Bartlett also is an uncle if reaffirmation was ever needed for a gene prescription.
This winter's Hawk player/coach, Paora Winitana, phoned to ask him to attend a scrimmage.
Sacked coach Liam Flynn was in touch with Marsh thereafter.
"It [Hawks stint] gives insight on what to work on and be competitive," he says, sponging skills off Tall Black and Hawks point guard Jarrod Kenny and "giving him a rest".
"JK and Paora have been the biggest influences."
Marsh says HBHS have a good chance of success next week considering three-quarters of the squad are seniors although he warns of the reliance factor.
"In previous times [losing finals] once we got on the big stage we were banking too much on our NZ reps," he says, stressing Wooten split the Hastings Boys' High School squad into two teams to ensure everyone got valuable minutes.
Last Friday and last night Hastings Boys' High School beat Napier Boys' High School by 10 and 9 points, respectively.
The hometown favourites also accounted for Palmerston North Boys' High School by eight points in Manawatu during their inter-school clash.
"We should finish first in our section," says Wooten although he expects a royal dogfight between New Plymouth , Rotorua and Hamilton in the other pool.
"Rotorua have the strongest team since I've been here," says the former Hawks coach of the Super 8 competition that is in its 15th year.
"We have seven really good teams so you'll have some great high-quality basketball at the arena."
HBHS open their account at 10.15am on Monday against PNBHS before hosting Gisborne at 2.45pm.
On Tuesday it'll be the Hastings Boys' High School v Napier Boys' High School derby tipping off at 10.15am before the crossovers from the top two qualifies (1 v 2) in the afternoon.
The final will be staged at 11.15am on Wednesday.