For accommodating the senior /senior plus market, I recommend you contact All Aboard Travel (
www.allaboardtravel.com) which specializes in trips for this demographic.
My parents (mid 70s age) sailed on Holland America and this travel agency helped with recommending the best deck, cabin near the elevator, trip insurance, hotel stay in Vancouver near the port, shuttle transfer from the hotel to the port, shore excursions that were intersting but not too rigorous, etc. The cabins on Holland America are larger sized which was a benefit for my parents.