There are typically 3 passes ...
First one is relatively easy. The next two more coral and a need to be able to turn 90 degrees. I've taken several times and have had no problems accept twice when I got scraped. The reason both times was because I was toward the rear of the 'line' and people in front of me stopped to take pictures, thus everyone was immediately in need of stopping quickly. I was in deeper water and could not easily stop and thus got scraped. Vendor stacks people to close together IMO.
To avoid make sure your toward the front of the line.