You would think that this is true. It certainly makes sense. What it doesn't do is to explain why they did not do this, because it's pretty clear that they didn't. For whatever reason, they relied on New York/New England controlled ships and shipping. I think this point needs further scrutiny, because I don't really understand why they didn't do this either.
They didn’t. The Navigation Act did NOTHING to stand in their way.
It precluded them from buying foreign ships or crew. If the US shipbuilders wouldn't sell to them, or would only sell to them at ridiculously exorbitant prices, then that navigation act did in fact stand in their way.
You need to loosen your tinfoil hat.