The useful comparison in Split is often a shorter Blue Lagoon outing against a longer custom island day. Start with the places your group cares about and the time you have. Then match that route to an actual vessel, rather than treating every “private boat” result as interchangeable.
Half day versus full day
A shorter outing leaves more room for lunch on land, an evening plan or a cautious return schedule. A longer charter gives your group more scope to agree stops with the skipper. Compare the advertised duration with hotel-to-hotel time, including transfers and the requested arrival before departure.
Capacity belongs to the boat option
Some listings sell several vessels under one title. Their limits can differ substantially. A group of ten cannot rely on the smallest option’s price or assume that a larger-looking premium vessel takes more passengers. Ask the operator to put the boat option and the full headcount in the confirmation.
Build one route-specific quote
Fuel can be separate on custom charters. Give the operator your preferred route and ask for the charge basis, not just a vague estimate for “a day out.” If a cave or distant stop is the reason for booking, ask whether the selected boat is appropriate for that route and what replaces the stop if conditions prevent it.
Three questions before you book
Which named boat option fits our entire party?
Is the skipper included, and how is fuel charged?
What route will you recommend for our booked duration?
Options to investigate
Read the capacity and cost notes, then confirm your exact date and boat with the provider.