The swimming team set the tone with four medals at Palermo's Olympic 50m pool with two bronzes for Becky Scaife in the 800m free, with 9.52.06 min, and the 400 individual medley with 5.38.63 min.
Rihanna Donaldson was second in a strong Jersey 200m freestyle, clocking 2.16.16 min, as Gemma Atherley just missed out in fourth with 2.17.56 min.
Donaldson then completed a strong last leg in the 4 x 100m freestyle to help Jersey to another silver medal in the relay with Atherley, Scaife, and Sian Cumming.
The Jersey team all clocked personal bests but missed out on the crucial National qualifying times they had hoped for.
Coach Dan Corden said: 'To beat Sardinia, who are a really big swimming nation at the Jeux des Iles, where it is normally between them and Sicily, really shows how strong the depth of our team is.'
• Full report and other results in today's JEP