You will not like my answer. I think they were "loaded" and "unloaded". I think you'll know where I'm going with this. Can someone local find out if the boats are still at those homes and whether they are two- or four-seaters?
The objective is to be alone with the victim ... it's much easier to walk 100 feet from the double gate to Maiden Lane. Staying on Maiden Lane would mean limited time with the victims. Perhaps, even an opportunist could find somewhere to go with two girls in 2-3 hours on a Friday afternoon.