I will be in Hanoi on a business trip and will be flying in arriving at 9:40 AM on a Saturday morning. I would like to get to Halong Bay that day and do a 2 day, 1 night Halong Bay cruise, getting back to Hanoi on Sunday night. Is this doable or do all the tours pick up in Hanoi a lot earlier? Is there any way to make this work arriving so late in the morning on Saturday? I have to be back in Hanoi for meetings on Monday morning.