We've been with the kids and loved it, it's a beautiful city
We did the P&O cruise ferry from Hull, it sails in the evening, the food is excellent and well worth the cost, a buffet of all different foods, really well prepared, there was entertainment put on, singer, bingo etc, go to bed, wake up in time for breakfast then it docks about 8am
We just did a friday night sailing, saturday in bruges by coach,(about 30 mins drive) pick up at 5.30 ish then the same in reverse, back in the UK 8am sunday morning, you can stay the night in a hotel so you'd be there all day sat and sun and arrive back in the UK monday morning but you'd need to find your hotel.
I have to say I really enjoyed it, something different, it's not the Queen Elizabeth but it was adequate though if I did it again i'd pay for the cabin upgrade.
Once you're on the boat you're not driving until sunday/monday morning so you don't have to worry about driving if you want a drink.