The Adriatic's most concentrated island cluster lies within fifteen nautical miles of Split's waterfront, a lattice of limestone outcrops that remained isolated from mainland road networks until the 1970s. Šolta, Čiovo and Drvenik Veli formed a defensive perimeter during Venetian rule, their shallow bays concealing supply routes that sustained Split's garrison when Ottoman forces reached the Dalmatian hinterland. The Blue Lagoon — a kidney-shaped basin between Drvenik Veli and Krknjaši islet — owes its luminous turquoise gradient to a seafloor of crushed shell and calcareous sand at depths rarely exceeding four metres, a composition that reflects midday sun in wavelengths the human eye registers as cyan. Split boat tours half day itineraries emerged as a commercial category in the early 2000s, designed to compress the archipelago's lagoon swimming, medieval harbour stops and island lunch landings into a four-to-five-hour window. Speedboat operators replaced the older wooden gajetas with rigid-hulled inflatables capable of twenty-five-knot cruising speeds, halving transit time between Split and the outer islands. The format appeals to cruise passengers on port calls and resort guests unwilling to forfeit an entire day; departure windows cluster between 08:00 and 09:00 to exploit calm morning seas and return passengers to Split by early afternoon. Trogir's UNESCO-listed core and Šolta's Maslinica harbour became fixed waypoints, their stone quays now accommodate simultaneous berthing of five to seven tour boats during July and August. The archipelago's appeal lies in bathymetric variety. Visitors swim in the Blue Lagoon's shallow sandy basin, then twenty minutes later anchor beside Šolta's volcanic cliffs where the seabed drops to eighteen metres within ten strokes of the shore. Maslinica's eighteenth-century Martinis Marchi castle — built as a fortified villa by Trogir nobility — serves as a visual anchor for the harbour stop; its crenellated towers frame the bay's eastern approach. Necujam Bay, carved into Šolta's southern coast, offers a pebble beach alternative when the Blue Lagoon holds too many vessels. Speedboat itineraries typically allocate ninety minutes for lagoon swimming, forty-five minutes in Trogir's old town, and thirty minutes at a Šolta harbour, with onboard travel consuming roughly two hours of the total excursion. The routes are weather-dependent; captains substitute Stomorska for Maslinica when southeasterly winds produce chop in the western channels. Local operators source crews from families with multi-generational fishing tenure in the archipelago, ensuring navigational knowledge of submerged rocks and seasonal current patterns that elude nautical charts.