I stopped in Ocracoke several weeks ago and braved the channel. I had to study the chart for several minutes to figure out how the markers work. The first couple of miles or so of Big Foot Slough channel heading into Silver Lake is red left, green right. That is because the channel goes out to Ocracoke Inlet so you are actually outbound on that part of the channel.
The Nine Foot Shoal Channel intersects from your right inbound so ignore its markers which are confusing. Follow the red/greens until you get to flashing red "SL". In actuality that marker is a red/green which makes a lot more sense as it is a green as you make a hard turn to port to enter the final channel into Silver Lake. Then the markers become red right returning into Silver Lake.
The NOAA chart is accurate except for SL being a red/green and once you figure out the marker sequence you will make it in fine.
Having been in and out once I would try the Nine Foot Shoal Channel as it is slightly more direct coming from Oriental, but for the first time use the Big Foot Slough Channel as it is a bit more straightforward and the ferry
boats come and go through it.
The NPS docks are pretty good. With a Golden Age Passport the cost is 60 cents per foot ($1.25 without) plus $3 for power and so you can't beat that deal.