He could have contested a double-handed category of the same class, but chose to go it alone and may now be regretting that decision.
"You can't turn back the clock," Sellers shakes his head in dismay. "These younger guys are a bit quicker around the boat, plus the fact you've got a main, a jib and a gennaker to operate ... and I've only ever been a skipper.
"Boat handling is letting me down badly - I'm missing my crew, there's no-one to give orders to."
At his age, Sellers is considered a great-grand-master in this fleet, which makes him sound wise, but today, just made him feel old.
While he still compares himself with the young whipper snappers at the head of the fleet, Sellers is still doing more than enough to head off his own contemporaries in the 65-74 age group.
He finished third overall in Saturday's practice race and placed in the top five in the first three counting races - fifth, third and third - before a ninth in the final race spoilt his record somewhat.
Former Olympian Jon Bilger, racing in the 45-54 group, gathered three wins to lead the standings, with Sellers in fifth.
His nearest great-grand-master challenge comes from Japanese Mamoru Aoki, 14 places and 39 points back.
"I led to the top mark in those first three, but lost them going downhill," reflects Sellers.
"That fourth one was probably a race too many for me today, though. [Organisers] must think we're supermen."
Sellers got himself in a tangle at the start of the last contest and although the winds had got up, he was not in a position to take advantage of his higher bodyweight.
"It's quite hard when you get back a bit and everyone is coming at you from all angles."
Sellers has not been lured back into the fray to make friends - he's still hungry for medals.
"I'm going to have to clean my act up a bit though," he says. "I'm not here to make up the numbers.
"I enjoy winning, but you have to accept the fact you're 66 years old and probably can't do thing as well.
"I am enjoying being back out on the water though and hope to continue after the Games."