Sunbed etiquette – what do you think?

I have just had a good customer return from a cruise aboard Celebrity Infinity, he had a terrible time with  a lack of sunbeds and fellow customers leaving their belongings on the sunbeds whilst they went off for hours at a time.

Apparently Celebrity have a ‘half hour rule’ whereby you shouldn’t leave your sunbed unattended for more than this time, however this was not enforced. P&O also state in their daily newspaper that they ‘do not condone reserving sunbeds’ however, again it is not enforced.

Is this something that you have come across? Which cruise lines are the best/worst for sunbed hogging? I’d love to hear your thoughts.