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@rick1zoo2 said, first thing would be to check how old/how many miles are on your shoes. That could be the answer.
How long was your run on the cruise? Did you run far enough to the point that your knee usually hurts?
I had something similar happen several years ago. My knee would start to hurt about mile 5, but wouldn’t hurt at all when I walked. I went to a sports chiropractor for a few weeks. She did some dry needling and scraping, but nothing for a while seemed to work. One week I had a half marathon where my knee hurt pretty badly, and I had to run/walk as I could to the finish (I was a continuous runner at that time). I had a half marathon the following week also, and I was worried about it. That week (in between races) she tried several new things. She dry needled and scraped in a new areas, did some cold laser therapy, and put on kinesiology tape. That next half marathon - no pain. It was so weird! From that point on for a while I taped my leg and I was pretty much good to go.
My pain was kind of on the outside, but a little on the back of my knee, I think. She taped it like a half moon around the outside of my knee cap and also a strip that started an inch or two below the back of my knee, and then went over the ligament (tendon??) on the back of my leg (the one on the outside) and continued about halfway up the back of my thigh. I don’t remember the stretch amounts now.
I’m not sure if that will help you. But I’ve also heard to put the tape where it hurts. I can add a picture if you’d like, but your pain may be different than mine.