For example I want to book at 4:45. Do i have to get there early or is any time before 4:45 okay?

You don't have to be there too early it takes time to boardYou don't have to be there real early it takes time to board but if you want a good seat you want to be there early But you can walk around the boat also

It is better to be there 30 min before. To make sure you are not late for check up and cruise departure.

I got there 30 minutes ahead of time and barely got a good seat. It was a Saturday though

Get there about 4:15 or so. You stand in a line down some steps. 20-30 minutes beforehand is good.

Get there earlier than your scheduled time. I would say at least 10 minutes beforehand to make sure you find it okay. There are chairs and benches to wait at the dock.

As I recall, the cruise takes off ~15 mins after the time you’ve booked.