Can only answer in respect of Princess cruises - they are very wheelchair friendly and have designated members of staff to assist any less able-bodied passengers - I am not speaking from experience but from observations made when on the princess ships.
Most modern ships are very wheel chair friendly some lines seem to be more helpful than others, not all tours and ports are suitable.Get in touch with a good agent and chat with them they will have feed back from customers and read some of the reviews on this site?
Thank you for taking the time to answer my question, very helpful.
There were a number of wheelchair users on last weeks Artemis Norwegian Fjord cruise. Some were with others, a few were on their own.
From what we saw, the P and O staff are competent and sensitive in dealing with wheelchair users and other handicapped persons, especially in places such as the Coral dining room .