On your 10th cruise and beyond you receive the Carnival Platinum Pins.
Prior to that there are pins available in the gift shop for about $5 each.
The gift shop pins are slightly different from the Platinum Pins.
8 Norwegian: Sky, Jewel, Dawn, Epic, Pearl, Breakaway, Getaway, Escape
10 Windjammer: S/V Legacy X3, S/V Polynesia, S/V Caledonia, S/V Diamant, S/V Sagitta X2 S/V Mandalay, S/V Vela