I'm not a writer so maybe somebody who is could take up this scenario.
Modern cruise ships are huge, up to 6,000 pasengers together for up to 4-6 weeks. Cruising is not a famliy holiday so most pasengers are adults, eithre single or couples. With so many people lots of activities are provided - swiming pools , climbing walls zip lines and , in some ships , a boxing ring in the gym.
https://www.google.co.uk/search?q=cruise+ship+boxing+ring&biw=1280&bih=913&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiJvoKLke7MAhXGC8AKHR9nDnwQsAQIKQNow imagine all those female passengers , many using the gym and seeing a ring being used. Maybe some are athletic, adventurous or just don't like a fellow pasenger. What better exercise than to see who is best in the ring - boxing, wrestling or both.
Or, as some cruises are more aimed at " swingers" some organised combat challenge set up for the women, and couples , to enter for a prize.
