In Roatan you will likely be going to Carnival's new Mahogany Bay dock.
No need for an excursion there. A fantastic new beach is right there within walking distance and it's free. There is a ski lift type ride that will take you over to the beach ($5 all day pass) but it's an easy walk. Beach chairs are free. There is also a zip line ($40) within easy walking distance.
7 Norwegian: Sky, Jewel, Dawn, Epic, Pearl, Breakaway, Getaway
9 Windjammer: S/V Legacy X3, S/V Polynesia, S/V Caledonia, S/V Diamant, S/V Sagitta X2 S/V Mandalay