I've been on 2 ultra-luxury cruise ships — endless caviar and free flights make the $685 per day worth it

However, many mass-market cruise companies are increasingly following the budget airline model: Charge a cheap fare and pile up plenty of irresistible pay-to-play amenities.

Travelers could easily accidentally blow past their budget by the end of the vacation.

Sure, luxury cruises have a higher base fare. But you'll never have to reach for your wallet once on board.

That's about as stress-free as you can get with a vacation.

"I'd rather have a few empty beds and get the right guests at the right price," Michael Ungerer, CEO of MSC Group's new luxury cruise line, Explora Journeys, told Business Insider in 2023. "Most of [the amenities] are already included, so we don't have to upsell."

In 2023, I spent one night on Explora Journeys' Explora I while it was docked in New York and three nights on Regent Seven Seas Cruises' Grandeur while it sailed roundtrip from Miami. Both were complimentary non-revenue events for travel agents and media.

Seven Seas Grandeur's least expensive 2024 cruise is a seven-night roundtrip Miami voyage in December, starting at $4,800 per person — about $685 per day. (Travelers can book their own flights and pre-cruise hotels for a discounted fare.)

Meanwhile, Explora I's most affordable itinerary is a $3,030-per-person, 10-night November sailing from Barcelona to Bridgetown, Barbados.

On both ships, the fare includes complimentary bottles of Champagne, WiFi, endless alcoholic beverages, and access to the spa.

With Regent Seven Seas, pre-cruise hotels, every on board restaurant, flights to and from the ship (business class if international), and most excursions are also included.

The 922-guest Explora I stands at 813 feet and 63,900 gross-tons. The 746-guest Seven Seas Grandeur is smaller at 735 feet-long and 55,000 gross-tons.

To compare, Royal Caribbean's most popular and the world's largest cruise ship, the 7,600-guest Icon of the Seas, is a casual 1,196 feet long and 248,663 gross tons.

But small ships have two big benefits: exclusivity and the ability to fit in more desirable ports.

The Grandeur is scheduled to sail to destinations like Oranjestad, Aruba, and Castries, Saint Lucia, while Explora I is planned for Hawaii and Casablanca, Morocco.

Icon of the Seas is exclusively sailing in the Caribbean this year.

Instead of arcades, Explora I and Seven Seas Grandeur have cigar lounges.

Instead of a kid's playground, the latter has a quiet library.

Even the drinking water is better: No need to travel to Erewhon to sip on crystal-infused water. Just head to Explora I's spa instead.

Explora I has the first Rolex store at sea. The Cartier boutique is right next door.

Up a few decks, travelers can workout at the Technogym Artis Line-supplied gym, where a treadmill costs $20,250 and an elliptical $15,500.

Meanwhile, Seven Seas Grandeur is decorated with 503 chandeliers and a $6 million art collection that includes several original Pablo Picasso pieces and a custom Fabergé egg.

Both floating five-star resorts have lunch buffets of raw seafood, lobster tails, and crab legs.

For dinner on the Explora I, travelers can dine on the six restaurants' wagyu tataki, grilled octopus, and aged prime rib with potatoes and caviar.

For a 10-night cruise, Regent Seven Seas says its new ship carries 1,200 pounds of lobster, 20 pounds of caviar, and 5,000 bottles of wine — the most pricey at $2,500.

Expensive food means expensive service: Like many high-end on-land restaurants, the hostess always offered me a black napkin when I wore dark pants.

And, they're free, according to the laws of "girl math."

By the end of my second night on the Regent Seven Seas ship, "I'm tired of eating caviar" went from being a joke to a serious statement.

But don't call Explora I's Lobby Bar, which looks like it came out of an actual hotel bar, "trashy." After all, its background music comes from the overhead Steinway piano.

But wealthy cruisers don't get to wake up with green siren-decorated cups of caffeine.

Instead, Explora I and Seven Seas Grandeur have their own coffee shops serving delectable espresso-based drinks and a separate afternoon tea service.

The smallest stateroom on the 461-cabin Explora I starts at 377 square-feet and flexes high-end amenities like a Dyson hairdryer.

The 373 cabins on the Seven Seas Grandeur start a bit smaller at 307 square-feet. At least it comes with L'Occitane en Provence products.

Both options have walk-in closets, floor-to-ceiling windows, and balconies. That's unheard of in the cheapest cabin on most mega-ships.

It's the general ambiance.

Ultra-luxury ships aren't designed for cruising families with young children. The two ships didn't have cartoonish decor, loud lounges, or an unbearable number of children that could've kicked my fight-or-flight response.

Instead, the high-end vessels' common spaces were modern, mature, and relaxing.

Popular cruise lines like Royal Caribbean, Norwegian, and Carnival have recently seen off-the-charts bookings.

The same applies to the industry's more niche and expensive peers — especially as travelers have increasingly splurged on luxurious vacations like small-ship cruising.

In February, Harry Sommer, president and CEO of Regent's parent company, Norwegian Cruise Line Holdings, said demand for its luxury brands has been "very high."

After eating caviar and black truffles for every dinner on the Grandeur, I now understand why.