Happy 50th birthday, Michelle!!!
Wow, going on a cruise without a single group is risky if you want to meet other singles. The best scenario is that you will meet plenty of other single people and you will get along with the fine, whether they be male or female. The worst is that you will meet just one and not get along with him or her.
Hang out at the disco the first few nights and you will get an idea what the rest of the cruise will be like.
Enjoy your cruise!!!