The Slovenian government has once again changed the entry regulations. To make a long story short: Transit is possible, and yacht owners and tourists can also re-enter Slovenia with a booking confirmation. Here is the link to the Slovenian government site, which published the news in English.
Translation of the text
We have taken the liberty of translating the text briefly for our readers.
Ljubljana, 26 May - The Slovenian government has added new exceptions to the quarantine rule for EU and Schengen nationals, allowing citizens from all over the EU to enter the country as tourists, provided they have a booking confirmation. The same applies to property owners in Slovenia. The new rules came into force on Friday, after the government adopted a new decree late Thursday that regulates border crossing not only with neighbouring countries but also with airports and ports. Under the latest rules, EU and Schengen nationals must be quarantined for 14 days upon arrival, unless they benefit from the now 17 exemptions. Most of these exceptions are for business purposes. These include tourists with confirmed reservations and persons owning real estate, boats or aircraft in Slovenia (together with their family members), daily border commuters, international freight forwarders and persons hired to provide urgent services (in the fields of energy, health care, transport and utilities). Some of the exceptions are for educational or health purposes. Persons who cross the border to seek health care, persons carrying out humanitarian transport, students entering Slovenia or the EU for educational purposes, and EU researchers and teachers working in Slovenia can thus enter without quarantine. Diplomats, persons attending a relative's funeral, persons who have close relatives or spouses in Slovenia, and persons who enter for a day to maintain contact with close relatives are also exempt from quarantine. There is a special exception for farmers who own property on both sides of the Slovenian borders. The exemptions are a kind of emergency solution, as EU countries are gradually reopening their borders on the basis of bilateral or multilateral agreements, instead of an EU-wide agreement that has so far proved elusive. Slovenia has so far signed such an agreement with Croatia, which means that its nationals can enter without restrictions. Third-country nationals (except if they are resident in Slovenia) must undergo a 14-day quarantine, but there are exceptions here too. These include carriers, diplomats, persons attending the funeral of a relative, persons providing urgent commercial services and persons in transit who enter and leave Slovenia on the same day.
Citizens from EU and Schengen countries may enter
To bring a little order to the Slovenian zigzag course on border opening, here is the summary: Yacht owners and real estate owners from the EU and the Schengen area are allowed to enter, as well as tourists from the EU and the Schengen area, provided they can show a valid booking confirmation when crossing the border.
Quarantine difficult to arrange for Austrians returning home
Now that Croatia, Slovenia and Germany, and from 3 June also Italy, have opened their borders, the 14-day quarantine on entry and return applies exclusively to Austria, although Austrian politicians had actually spoken of “concerted action” in advance.