Start with the clock, not the water
The honest way to choose is to ask how much of the day you can give away. A beach club on Tierra Bomba eats the whole thing: you're on a 10am or 11.30am boat and you're not back until 4.30pm at the earliest. A rooftop pool costs you nothing but the walk upstairs, and you can bail out at 2pm to go do something else. Both are good days. They're just not interchangeable, and people who treat them as interchangeable are the ones sprinting to a pier at 11.25.
We have skin in both games, so here's the disclosure up front: the rooftop is ours, and Blue Apple Beach is our big sister isleña on Tierra Bomba. We'll still tell you which one your day wants.
The boat day, in full
Blue Apple Beach is a beach club and hotel on Tierra Bomba, next to Bocachica Village, about a 30-minute ride from Cartagena. The shuttle runs from Cartagena at 10am and 11.30am, and back at 4pm and 5.30pm. You can also turn up on your own boat. The beach club is open 10.30am to 6pm and the restaurant and bar keep going until 11pm.
A club day pass covering boat and access is around US $40, with food and drinks a la carte. There's an all-in-one pass at around US $80 that folds in lunch and a cocktail, but it's Monday to Friday only and excludes holidays and high season, so weekend visitors are on the club pass. The pass includes the pool, the full restaurant and bar, beach volleyball, SUP and the outdoor gym at no extra cost. Shade is the thing you pay for separately: a garden lounger is $5, a poolside single lounger is $10, a VIP beach cabaña for up to three is $30, and a poolside daybed for up to six is $50, all including shade and towel hire.
Two things worth knowing before you commit. Weekdays are quieter; weekends bring a DJ and a livelier room. And because it sits closer in than the Rosario Islands, you can stop there on the way back from Rosario for a late lunch or a sunset drink rather than making it the whole plan. It's solar-powered, zero-waste driven and B-Corp certified through Fundación Green Apple, and it's listed by MICHELIN, Condé Nast and TripAdvisor for both hotel and restaurant. Access is by day pass, not something bundled into a stay with us.
The rooftop day, in full
Ours is the low-effort option and we're unapologetic about it. We were the first hotel in the city to open our rooftop to the public, so you don't have to be a guest. It's open 8am to midnight, every day, with a cocktail bar, an all day diner and two little plunge pools. Breakfast runs until midday, 11am on weekends. Happy hour specials run daily. A pool day pass is 25 euros for two people.
What it is not: the sea. They're plunge pools, built for sitting in with a drink while the afternoon burns off, not for swimming lengths. If that sounds like a downgrade, take the boat. If you've already done two island days and your shoulders have had enough, it's the correct call.
Sundays it turns into Sunday Ritual from 11am: entry covers unlimited mimosas and beer, food is separate at special prices, and there are no jeans allowed. After dark it gets loud, which is deliberate. Children are welcome until 8pm, under 12s free during the day, and after 8pm it's adults only.
Who should pick which
Take the boat if you have a clear full day, you want actual ocean, you're travelling as a group that wants volleyball and a DJ, or you're diving or riding horses. Stay on the roof if it's your arrival or departure day, if rain is threatening and you don't want to be stranded on an island in it, if you have small children whose tolerance for boats is theoretical, or if you want to swim for two hours and still make a 1pm museum.
And if you're greedy: do the boat on a weekday when the all-in-one pass is available and the island is calmer, then keep the rooftop for the day you fly out.