I concur with Jon big time. The run through Diamond Shoals is much greater than 8 miles offshore. I have come through there a number of times when the regular ocean swells of 4-6 ft were accentuated to 10-12 in the shoals going out 35 miles. If ypu look carefully the Atlantic goes from a couple thousand feet deep to about 100 ft in less than 3 miles. And instead of large intervals the Hatteras area had steep short intervals. There is no real place to duck in for cover as discussed that in any weather Ocracoke is not an option, and Oregon is never and option. The winds in this area not as predictable as you think either. You have many factors to consider. Down sloping winds from the mountains, short coastal plain, influence from tropical air masses meeting fronts from Canada. This can change the weather in the area quite quickly and dramatically.
What most people do not understand about the charts and Jon explained well is that these two areas as well as many of the inlets on the Jersey Shore, the sand shift daily around the channels and the CG is constantly reconfiguring temporary bouys defining them. That should tell you something about the conditions you will find there.
Auspicious has takenthe outside route many times ( I don't want to speak for him) but I don't beleive he runs the coast, certainly not at 3 miles. I thought is route was many outside the stream. He has a world of experience and is very cautious as a delivery captain, and has great experience in this area.
Personally I would not risk my boat, or life on this route and would come out after Hatteras on the way south. There is a reason it is called the graveyard of the Atlantic.
Dave
While Hatteras most certainly deserves the utmost respect, I also think some of the cautionary advice here might be a bit overwrought. Frankly, most of my trips out around have been fairly tame, or afforded some very nice sailing... Several have been motor jobs in a flat calm...
My main point is I simply don't see the value of that route from the Chesapeake as opposed to the ICW, unless you're gonna continue on until Charleston, or at least Wrightsville... If you wind up stopping in Beaufort, going down outside, even cutting the corner at Diamond Shoals as closely as possible, still adds roughly 40 miles to the total distance from Hampton Roads over the run inside... Not sure what sort of boat the OP is taking south, but if he does wind up with a calm weather window that mandates a lot of motoring, chances are he's gonna have to put into Beaufort for fuel, anyway...
If time is of the essence, run through the gauntlet of restricted bridges south of Norfolk at night, or early in the AM before they go on restriction... Stop in Coinjock, treat yourself to a great dinner, run through the following night down Pamlico Sound, you'll still be in Beaufort early the next day... I just think the OP is overestimating the time saving by going outside, unless they turn out to be incredibly lucky with the weather, and have conditions favorable for staying outside all the way to Charleston... And when that happens, it generally means a fairly sporty trip out around Frying Pan/Cape Fear, and a very tired crew of two by the time you hit Charleston...
There appears to be an eddy running North to South close to the shore. This seems to be a common feature of the stream - that an eddy runs in the opposite direction outside the path of the Gulf Stream.
Why not ride the eddy south?
Why not sail/motor inside Diamond Shoals during the daytime instead of outside? I understand the danger of being caught on a lee shore, but if you pick the right weather window, it should work.
Perhaps there's something there, but I have never noticed a consistent counter-current running down the beach... there's always something going on about 15 miles north of Oregon Inlet, the water there is generally confused by some sort of eddy, but that's about it, I've never been able to figure out how to play it to any particular advantage...
I'm no expert on this subject but thought I had read somewhere that anyone doing the outside heading south did so on the east side of the GS. Does this make sense?
For the trip the OP has in mind - coming down the Chesapeake, and planning to stop in Beaufort or Charleston - it makes no sense whatsoever, ESPECIALLY for an ICW-capable boat that doesn't have to go around Hatteras to begin with... Such a route would add a ridiculous amount of time and distance to the trip...
Passing east of the Stream can make sense on a voyage coming from New England, perhaps, and continuing straight onto S. Florida or the Bahamas... But coming out of the Chesapeake or coming coastwise from NY, I think simply waiting in Hampton until a weather window presents itself is the only way to go...
I've always run pretty much right down the beach, and rounded Diamond Shoals at the red nun "2", no problem... But, as Dave on AUSPICIOUS mentioned, you definitely have to be "paying attention" in that neighborhood...