The short version
Tierra Bomba for a half day, the Rosario Islands for a full one. That's the whole decision, and most people overthink it.
We're on Carrera 7 in San Diego, inside the walls, and this is the question we get more than any other: guests want one good beach day and they've read forty conflicting blogs about it. Here's how we actually answer it at the bar.
Cartagena's city beaches are not why you flew here. The water you're picturing is offshore, which means a boat, which means a decision about how much of your day you're willing to hand over to that boat. Tierra Bomba is the island sitting directly across the bay from the old city, 15 to 20 minutes away by private boat, with a local ferry and water taxis running from the Bocagrande side too. The Rosario Islands are an archipelago further out, roughly an hour each way depending on your boat and the chop.
Side by side
Prices below are what tour operators were publishing when we wrote this, in 2026. Treat them as a ballpark and check before you book, because boat pricing here moves with fuel and season.
Pick Tierra Bomba if
You have one beach day, or you want a beach half day. The short crossing is the entire argument: you can have breakfast with us, be on a day bed by mid-morning, and be back inside the walls in time to shower before dinner. It also means you're not committed. If the sky turns, and in September and October it sometimes does, you're 20 minutes from your room rather than an hour and a bit.
Blue Apple Beach is ours, on Tierra Bomba, so we'll be straight with you about the bias. It's also why we can sort out your day properly rather than pointing you at a pier. Bring cash and a dry bag if you're going to take a local water taxi. It's a small boat and spray happens. Or book a spot on the Blue Apple boat, which is a far more comfortable ride direct to the Blue Apple Beach dock.
The honest downside: Tierra Bomba's water is good, not postcard-unreal. You are still in the bay. People who came to Colombia specifically for clear Caribbean water sometimes want more.
Pick the Rosario Islands if
Water clarity is the reason you booked the flight, and you'll trade a whole day for it. The islands sit further offshore inside a national park area, the water genuinely looks like the photos, and there's snorkelling worth doing. Day passes at island beach clubs generally start around 75 USD before extras, and there's a small dock fee, around 25,000 COP, that you pay in cash on the way out. Bring notes; cards are not a given at a pier.
What nobody tells you: shared boats leave early, run on their own schedule, and you don't control when you come back. That's fine if it's your only plan for the day. It's miserable if you booked a 2pm walking tour. If your group is four or more, a private boat is often the better call for the freedom rather than the luxury.
What we'd do with three days
One beach day, not two. We'd spend it on Tierra Bomba, keep the following morning for the walls and the museums, and use the rooftop for the part of the afternoon when nobody sensible is outside. It's open till midnight and it gets loud after dark, which is the point. If you want quiet and colonial hush, we're probably not your spot.
If you're here five nights or more, then yes, do both. Rosario first while you're fresh, Tierra Bomba later in the week when you've stopped wanting to achieve things.
Practical things worth knowing
Book the boat the day before, not the morning of. Breakfast is included with us if you book direct through our site, so eat before you go rather than paying beach club prices for eggs. And whichever island you pick, take twice the sunscreen you think you need. The breeze on the water lies to you.
Live Cartagena the way we do: one island, a long lunch, and back up here for sunset.