Blå Grotte – Privattur

The Blue Cave day is the most-booked trip out of Split and the one where a private boat changes the most. On the group departure the day is a fixed ten hours with eleven other people and a schedule that does not bend. Privately it is the same coastline with the clock in your hands.

The difference shows up at the cave itself. Boats queue at Mezzoporat on Biševo and the wait swings between ten minutes and an hour depending on the hour and the month. On a private charter the skipper reads the queue: if it is long, we anchor for a swim first and come back when it has thinned. On a group boat you join the back of it because eleven other people have somewhere to be.

The second difference is the afternoon. Hvar gets sixty minutes on the group day because the boat has to be back. Privately you stay as long as lunch takes, and the last swim happens wherever the skipper thinks the water is best that afternoon rather than wherever the itinerary says.

The boat is €1,300 for up to twelve people. Twelve seats on the group Blue Cave day at €119 is €1,428, so at full capacity the private charter is already cheaper — and you are not sharing the boat.

The crossover is around eleven people. Below that you are paying a premium for exclusivity and pace; above it you are simply paying less. Groups of eight to ten usually decide it is worth the difference once they understand what the pace buys, and groups of eleven or more book it on price alone.

What is in the number: skipper and sailor, fuel, mooring fees, insurance, snorkel gear, wind jackets and water. What is not: the Blue Cave entrance fee, which is €24 per adult from 20 June to 10 September and €18 outside those dates, paid in cash on Biševo, and lunch in Hvar.

Departure is early because the cave decides — 07:00 between 16 June and 15 September, 07:45 in the shoulder months, timed so the boat is at Biševo inside the light window between roughly 10:00 and 12:00.

After the cave the route runs to Stiniva on Vis, the cliff-walled cove voted Europe's best beach in 2016, then to Budikovac lagoon for the calmest snorkelling water of the day. Hvar old town is lunch. The Pakleni islands are the last swim, and the skipper picks whichever bay is quietest that hour.

Everything after the cave is negotiable. Groups with small children usually trade Hvar time for more time at Budikovac. Groups who came for the swimming skip the town almost entirely. Photographers ask for the Stiniva approach twice. None of that is possible on a shared boat.

Families with children under eight, because the shallow stops can run long and the crossings can be broken up. Groups of eight or more, on price. Anyone who has a fixed lunch reservation in Hvar. And anyone who has done the group version before and knows exactly which two stops they want doubled.

Who should not: two people on a budget. At €1,300 the group departure is the sensible choice for a couple, and the day is genuinely good. If your group is small but you still want the private pace, the 3 Island private route covers sheltered water at €1,100 and is easier on anyone prone to seasickness.

A 15% deposit holds the date, the balance is settled on the day, and cancellation is free up to seven days before departure.

Private charters do not have to start on the Split Riva. The skipper can collect a group from most marinas and waterfront hotels within about three nautical miles of the city centre at no extra cost — Marina Kaštela, ACI Split, the Meje and Žnjan waterfronts, and the pontoons in front of several of the seafront hotels.

Trogir works too and is often better if your accommodation is on that side: it shaves the road transfer entirely and the run out to Biševo is barely longer. Split Airport guests frequently start from Trogir for exactly that reason.

Anything further out is possible with an adjusted meeting point or a small surcharge. Tell us where you are staying when you enquire and the skipper will name the nearest sensible pier rather than making you cross the city at six in the morning.

The cave itself is at its best from late May to early September, when the sun is high enough to push light through the underwater opening at full strength. Outside that the effect still happens but the blue is softer.

June and September are the two months worth booking. The light is as good as July and August, the sea is warm, and the queue at Mezzoporat is a fraction of what it is in high summer — which on a private boat matters less than it does on a group day, but still buys you an extra half hour somewhere better.

July and August work, and most people come then anyway. Expect the cave queue to run towards an hour at the wrong time of day and plan the swim-first approach. April, early May and late October are for people who care more about having Stiniva to themselves than about the cave being at peak.

For a month-by-month breakdown of sea temperature and crowds, the Blue Cave by month guide covers it properly.