In Italy you can get very good 2nd hand sailing boat, on good price (much cheaper then in Croatia)
Renting of boat is also possible.
In Croatian part of Adriatic you can cruise with boat, among 1000 islands, and only maybe 10% of them are inhabitted. This is true mediteranean wilderness.
In mediteranean only Greek coast is more diverse with number of islands double then that.
If renting the boat, during summer (june till august) rental fee is high, but from septemebr onwards renting fee drops quite a lot, utill june.
Biking is popular, especialy in Istria (west part of Croatia close to Italy) where bikers go from one guest house to another, where all places are bikers friendly, and countryside is great! Local scenery roads, away from higheways, wineyards, valleys, villages, etc
Hunting is good. Croatia has one of the denseist population of brown bears in this part of EU.
Boar numbers are growing, etc..
All you need is enough spare time, and some money to spend! For hunting, and trophy system - drop me a pm, because prices depend on trophy size. You may need an advise on that.