A lack of wind and the looming threat of thunderstorms in the region around Santander, Spain, made it tough for officials and competitors.
Robert Scheidt suffered in particular as the Brazilian began the day with a two-point lead in the men's laser, but ended Sunday in fourth.
Maloney did impress, though, after the laser gold fleet were initially called back to port as the black flag was issued.
The New Zealand native initially fell some 150 metres behind Dutchman Nicholas Heiner, but he eventually stole a 200m lead and finished over a minute ahead of his rivals, taking his overall standing to 12th.
Australian Tom Burton ended up taking ninth as he looked unwilling to take many risks, sticking to the centre of the course for much of the race, but Maloney was happy to capitalise on his rivals' apparent nervousness.
Maloney said: "After a fair bit of time spent waiting around for the wind to come in, we managed to complete one gold fleet race and taking the win was a good way to begin the finals series.
"We have a reserve day tomorrow, so a bit of time to refresh mentally for the second half of the event."
And Burton, who was keen to highlight the impact of the day's conditions, added: "It was pretty much snakes and ladders.
"With the tide there was a lot of stuff going on, that and the wind shifts. You couldn't change sides. If you tried too hard [to find the favourable winds] you could be in even worse trouble.
"You had to play what you got."
Things were no easier for competitors in the 470 discipline, although that was as much to do with human error as adverse weather conditions.
After a significant delay, the male competitors were called back in with a general recall and then the race was forced to be halted midway through the second leg, as it was discovered the course had no bottom gate.
Sofian Bouvet and Jeremie Mion of France and American duo Stuart McNay and David Hughes were the winners on the day in the men's event.
The French were also successful in the women's 470, as Maelenn Lemaitre and Aloise Retornaz claimed victory, while China's Dongshuan Zhang was the only victor in the women's laser radial.
Charlene Picon, also of France, retained the lead in the women's RS:X, mostly thanks to first and second-place finishes from two of the four races, keeping herself seven points ahead of Bryony Shaw of Great Britain.
There is a new leader in the men's RS:X, with Poland's Piotr Myska sitting top with eight points, two ahead of a group of rivals following a second-placed finish in the fourth race, helping to lift him above Pierre le Coq and Louis Giard, who held a joint overnight lead.