During the next decades the club continually participated at the First Division (with the exception of six seasons in the Second Division/A2 Ethniki).

The club also reached 8 times the final of the Greek Water Polo Cup, winning the trophy in 1995.

The team was the Greek Cup Winner in 1995, when they defeated Vouliagmeni 13-12 in the OAKA Indoor Aquatic Centre.

Before reaching the final, NOP had eliminated Montpellier, Crişul Oradea, Adalar and Dynamo Lviv.

In the quarter-finals they defeated Primorac Kotor and in the semi-finals the Real Canoe NC.