Based on my personal experiences, you have this backwards. Unless you have very young kids with you who are walking, once you've exited the park it shouldn't take more than about 20 minutes (give or take a few) to do the walk if you keep a steady pace. I did it with my 9 and 7 year olds a couple of weeks ago. How long the boat takes depends entirely on how long you have to wait for a boat. When we did that walk a couple of weeks ago a boat had left the dock a couple minutes before we got there, so we decided to walk. When we got to the bridge to the Yacht Club the next boat that we would have been on wasn't even in sight on the way back. While our walk took about 20 minutes, had we waited for the boat is would have been 30+. Yes, if you happen to get to the dock at the studios and a boat is waiting for you the trip wouldn't be more than 20 minutes, but on average you can plan on the boat being 30 minutes, and we've done it quite frequently.