I went to Dubrovnik in May but (a) was there with friends for a wedding and (b) the weather was unseasonably awful so couldn't do much. Thankfully the wedding wasn't affected but there were no boat trip running to islands and the cable car wasn't running while we were there.

I've decided to go back in a few weeks on my own for a short break to do some of the stuff we missed.

One thing we did manage to do on one of the few good afternoons was the walk around the walls and I'm aware of the Buža Bar (although it was rammed when we tried to get in so we skipped it).
I'd like to go up the cable car and am staying near the bottom station so that's that one sorted.
I'd also like to go on an 'Islands Boat Trip' - because the weren't running we didn't really look into them so I'm wondering if there are different boat trips available, best place to get one from etc?
Apart from the stuff I've done or know about (walls, boat trip and cable car) is there anything else I should be looking at? If not, that's fine - I'm only there for four days and if I do 'stuff' for two days and lounge by the pool and read for two days, I'd be quite happy.
I won't have any transport of my own but if there was somewhere near Dubrovnik worth seeing that's doable with public transport, I'd consider that too.

p.s. I've never watched Game Of Thrones so have no interest in any connection to that (although I believe I have walked the 'Steps Of Shame')