I don’t get that either. How is Castaway Cay a Gillian’s island experience?
Castaway Cay is a VERY different experience than what
Royal Caribbean built at Coco Cay.
Some portion of cruisers want the CoCo Cay experience, pools, slides, club like atmosphere.
Some portion of cruisers want a beach experience something akin to glamping. A beach experience that makes you feel like you are isolated but pampered.
When I first started cruising, private islands were very basic. You can still get that same original experience at Princess Cay. I don't think much development has occurred there since it was built decades ago.
Some closest to the Gilligan experience are Castaway Cay, Half Moon Cay, Princess Cay, Ocean Cay, and Great Stirrup Cay.
There there are those with more amenities like Labadee and Harvest Cay but not as much as CoCo Cay.
There are three private "islands" coming soon. Lighthouse Point, RCCL Nassau Beach Club, and Celebration Key.
1/3 are Gilligan (Glamping) style, 2/3 are Miami Beach Club style.
At all of them I have not had a problem finding an isolated spot and getting the experience I want.