What ship? If you book a spa cabin, you get access to spa amenities. See below from Carnival’s web site. If it is one of the newer ships, it is worth it for the thermal suite.
Cloud 9 Spa™ staterooms do things a little different than ordinary staterooms. For starters, we dare you to cross the threshold without feeling a little more relaxed. Once you're inside, you'll find pleasing decor and in-room amenities like ELEMIS bath products and spa-branded bathrobes and slippers to enhance your stay.
What’s more, your excellent stateroom choice gets you priority spa reservations, free fitness classes, unlimited access to the thermal suites, exclusive discounts on treatments during port days... and more. (And on ships with a Hydrotherapy Pool, you’re welcome to use it as much as you want!)
And the best part? We've got a full range of rooms with that Cloud 9 mojo, from cozy Interiors to stretch-out Suites, ensuring you'll never have to sacrifice comfort for value.