Robin,
The current in the Hatteras area appears to be more a factor of the movement of offshore waters and not the dirunal tidal flow. It is the proximity and strength of the Gulf Stream that determines the amount of current that we have on the offshore wreck sites during the summer season.
The tide does effect the near shore conditions and of course the effect of tidal flow on the inlet is significant. There is also some effect of tide on the shoals area, but even in that area the current is more controlled by the the flow and strength of offshore water currents.
That said, the water that a high tide moves around does have to go somewhere and so it will have some effect on local water flows near shore, it just does not appear to be a significant factor on the offshore wrecks.
