Here's what I did to deal with the glasses/mask problem:
I brought my own mask (Body Glove kit from Costco, highly recommended), so I can't say for sure whether this method will work with the CC masks. I have a pair of prescription safety glasses from work (slightly stronger frame, thicker lenses), and I removed the side earpieces (what are those called anyway?), leaving just the lenses with the front part of the frame and the nose pads.
I was able to mount the glasses in the mask by sticking each side of the frame into the silicone on each side of the mask. The glasses actually stayed in place pretty well, and for the first time in my life, I could see underwater! It's not optimal (extra surfaces for droplets and fogging), but definitely cheaper than contacts or prescription masks, at least for a single vacation.
This could probably work with non-safety glasses, although some weaker wire frames might bend under the stress. And I really don't know if it would work with the CC masks - but you could always bring some sticky wax or something (duct tape?) to mount the glasses in place.
Here's the snorkel set I used:
snorkel set. Unfortunately, it's not available at Costco at the moment, but we found a set on eBay back in February.
Good luck - and have a great cruise!
April