In Vstep's defence, the depths aren't wrong. They are simply modelled on the lowest possible tides. They had to select some state of the tide and they chose the chart datum depths. That may be inconveient, but it isn't wrong. It does present some logistical challenges, of course.
Also, not all the harbours are incorect. For instance, Padstow is correctly modelled, but on about 2/3 tide. The charts correctly show CD depths and the vessels then have several metres more water, which is entirely appropriate.
New York has a problem, but that is a matter of being too deep. The charts used by Vstep showed the depth in feet, but it was believed that it was shown in metres. Having seen the charts, I can understand the confusion.
I am currently working with them on Portsmouth, Southampton and other Solent areas. The changes are not a five minute job, unfortunately.
If you want versions of ships that have reduced drafts, that can access most harbours, you can download them from Creators Forum (click on the link on my signature).