We like the Miami Marriott Biscayne Bay. They are right on the water and many rooms have an incredible view of the port. There are shops and restaurants (there is a really good little Italian place) within the hotel as they share a mall area with the Double Tree next door. It is not within close walking distance (20+ minutes walk) to the Bayside MarketPlace, but it is only about a block from the free monorail system that runs around the downtown area so you can get to within a couple of blocks of that popular shopping area with that service. Last time, in October, we took Uber out to South Beach / Lincoln Road, only took about 10 minutes and $10. Cab fare to the port is usually like $15 with tip. There is also a really nice Publix about a block away so it is easy to pick up any last minute items you may need.