Another idea.... ok a friend of mine has some old scuba equipment that he doesn't want any more. Until now, I never thought to take it because I didn't want to maintain it (and so would rent instead).
However, what if I take this equipment and maintain it enough to do pool practice dives? I would never actually use it do scuba more than 15' and no where but a pool.
Scuba equipment should be maintained properly no matter where or to what depth you are using it. You don't mention if that equipment includes a tank, but it shouldn't be filled if it has not been viz'd within 1 year and within 5 years of a hydro. All of your gear is your life support.
My LDS charges $25 for a refresher in the pool, so hopefully you can find something more reasonable in your area. You may be able to ask the cruise/dive op if it would count if you practice skills in the pool and log it as a dive if someone verifies that you did that? Some LDS' have practice pool nights or Discover Scuba experiences where you could practice for your own benefit even if they won't officially count.
I've encountered the recent experience or check-out dive requirement several times in the last 6 years or so. In Belize, before doing the Blue Hole with our dive op, everyone needed to be observed on other dives before being allowed to book the Blue Hole, even my Instructor dive buddy.
In the Florida Keys, we were informed by the dive op that everyone had to have logged dives within the last 6 months. I was prepared to show them my log book/computer, but no one followed up. However, I was travelling with a group and the LDS owner had already vouched for us.
In Egypt, everyone was required to do a check-out dive before doing any boat dive. I booked it the afternoon I got there to not lose the full day dives the rest of the week. Through email in advance, they asked for my training agency, certification #, date of last dive, depth and temp/conditions of the last dive. When I got there, they had it handy and asked if that was still my last dive 2 weeks ago and checked my log book and asked for my computer, verifying the info and looking at previous dives. We splashed, did a weighting check, I hovered patiently while they did a few skills with others and off we went. No big deal and we had a good shore dive.
So yes, I'd say that more dive ops seem to be taking an interest in recent dive experience, so I'd rather be prepared than sorry. If you book your own dives wherever possible or find out the policies of the dive op the cruise is using, you can find out in advance and be prepared. Though it would serve you well to be prepared anyway...