The Blue Lagoon, slowly — a guide to Krknjaši

There is a particular shade of turquoise that the Blue Lagoon does in late morning. It is the seabed, not the camera. Here is how to see it the way it deserves.

Where it is

Krknjaši is a shallow, sandy bay on the eastern side of Drvenik Veli, sheltered by two small islets — Krknjaš Veli and Krknjaš Mali. Roughly an hour by boat from Trogir. The depth across most of the lagoon is between 2 and 5 metres, which is why the colour reads turquoise instead of the usual deeper blue.

When to go

The lagoon has two different lives. Before 11:00 it belongs to whoever arrives early — usually a handful of private and small-group boats. By midday a few of the larger day-cruise operators arrive and the bay turns into something busier. By 15:00 it has quieted again.

If you are planning your day, aim for one of the two quieter windows. The 09:30–11:00 window has the best light for photographs; the late-afternoon window has the better swimming because the water is warmer.

What you’ll see under the surface

The seabed in Krknjaši is mostly sand and Posidonia oceanica — the Mediterranean seagrass that gives the water its clarity and supports the small fish populations the bay is known for. The seagrass meadows are protected. You should not stand on them or anchor in them; we use the marked mooring buoys.

Snorkelling is genuinely worth it. The visibility is often 10 metres or more in the morning. You will see saddled seabream, white seabream, the occasional octopus in the rocks at the edge of the lagoon, and, if you are very early, sometimes a group of bottlenose dolphins in the channel between the islets.

How to be a good visitor

• Use reef-safe sunscreen, or apply sunscreen 20 minutes before swimming.
• Do not feed the fish — it changes the food web fast and is not allowed.
• Do not anchor in the seagrass. Use the marked mooring buoys.
• Take everything back to the boat. The lagoon has no waste service.