Vacation life on a big ship has few negative moments, unless you want to eat lunch at exactly the same time and place as the multitudes that daily descend on the buffet restaurant near the pool.

In a week cruising on the gigantic Oasis of the Seas, crowds were not much of an issue. On a ship that holds up to 6,000 passengers, I zipped aboard in Fort Lauderdale (a breeze at 2 p.m.), and seven nights later walked off just as quickly. At sea, I had no problem finding a free deck chair, an elevator or an alternative restaurant seat. After the first day, I skipped the buffet (Windjammer Marketplace) between noon and 1:30 p.m.

My biggest problem on Oasis: Checking off everything on my long to-do and to-eat lists, which is something to note if you are one of those non-cruisers who fears being bored. Either way, active or relaxing, my dance card usually was booked for the day, including the three at sea between Florida and Cozumel, Mexico.

With twin sister Allure of the Seas, Royal Caribbean’s Oasis is world’s largest passenger ship. On dozens of other cruises, I just showed up, looked around and meandered my way through the week. Not on Oasis. Without a plan, I might have missed something glazed at the donut shop, an onion ring at Johnny Rockets, the packed evening comedy club, a Hairspray performance, or a high dive show at the outdoor pool theater. So, at home, before the cruise, I made lists of activities and eating choices.

I kept a budget. Not a gambler or a big drinker, I didn’t add up expenses on past cruises until the end of the week. But with tips now at $11 or so per person per day, and many onboard activities and special meals carrying a price tag, I noted daily expenses. I budgeted roughly $300 for the week, including tips ($80), fees for specialty restaurants ($100) and bar bills. Instead, I spent nearly $500, which is why, near the end of the week, I decided to skip two of the fee-based alternative restaurants.

From a financial perspective, a week aboard Oasis was a tale of two ships, so much for free, so much with a price tag. Many passengers probably fit into one of two roles — folks with some extra bucks to spend and others sailing on a strict budget — so I decided to bounce back and forth between pricey and cheap.

Oasis is well designed to accommodate either role.

When feeling flush, I dined well at the best alternative restaurants for dinner: 150 Central Park ($40 fee for a six-course gourmet meal, including scallops, a Wagyu strip and six kinds of salt for the sourdough rolls, $21 for two glasses of wine) and Chops Grill ($30 fee for a fine steakhouse dinner, $65 for a bottle of Bordeaux that I drank over two nights). I also tasted tapas at Vintages wine bar ($11.50).

I splurged on a deep tissue massage ($150 with tip), which was necessary, and successful, to deal with a sore lower back, the result of several plane rides on my way to Florida. After the spa treatment, I walked without pain for the rest of the week.

I wasted $10.24 for dinner at the Seafood Shack on the Boardwalk, where everything is heavily breaded and deep fried, much more than my tummy was used to. Royal Caribbean may have achieved its goal of serving Boardwalk food with authentic tastes from Atlantic City. But why would they want to?

A Boardwalk lunch was fun at Johnny Rockets, where the $4.95 fee includes a burger, onion rings and dessert. Is the burger better than the free one upstairs in the buffet restaurant? No, but I could sit outside and listen to some great old rock music. My waitress was bubbly good. She insisted that I try the apple pie a la mode, and when she returned to clear the table, she eyed the empty pie plate, eyebrows raised.