I haven’t done an hour-long rental myself, but I was on a yacht for a couple of hours last year with some colleagues. We cruised around the Marina, and even that short time felt special with the city lights and water views. For 6 people, I’d guess a smaller yacht, maybe 35-45 feet, would be cozy but nice. You might want to ask if they allow quick trips, as some companies have minimums. Are you thinking of a specific time, like sunset, or just a daytime vibe? Either way, the Dubai coast is gorgeous, so you’ll love it!