Well I can guarantee that you won't be diving on a sandbar. The only question will be how much of the site you will be able to "see" because of the visibility. As with any diving there is no way to make any promises but the QAR DiveDown dives are being timed with the tides to try to maximize visibility. On average we expect around 5 feet up to 10 feet on a good day with the tides. I've seen days though with vis over 50 feet.
Without getting too technical (and boring) the sand in the ebb tidal delta is in constant migration. Some back and forth but primarily east to west. Think blowing sand in the desert. As the top few inches of sand moves west with current sand from the east comes in to replace it. The navigational channel .6 miles east of the site means the sand that would move in to replace what is leaving gets scooped out by the Corp maintaining the channel and placed in the near shore disposal area west of the site. Bottom line: no replenishing sand, less protection for artifacts, exposure, loss in storms. This is an experiment to see if we can artificially introduce the sand to slow the erosion, until we can get funding.
To answer your management question, it is a combination of the reasons you mention.
While as a general rule for archaeology we try to leave sites "in situ" and undisturbed; that is not really an option for the QAR because of its environment. Everyone agrees that the best preservation for this site is systematic, mapping, excavation, and recovery. The primary problem we have is funding. As all divers know, bottom time, boat diving, is not inexpensive. In 2005, researchers spent a total of 22 days diving on site for 235 hours 15 minutes of total bottom time. Beyond the water work, there is the conservation and preservation of the artifacts.
The environment dictates some limitations for us as well. Because of location our best work windows are spring and fall even though spring presents the lingering water temperature problems, and fall means we are dodging tropical systems.
Our best estimates are that if we had full funding we could excavate and recover the site in 3-4 years (6-8 field seasons). The follow up conservation work will likely take another 6-10 years to complete.
I'll see if I can post some pics from the site to a photo gallery to give everyone a glimpse, and I'll probably see you with DiveDown as I'm slated to lecture and supervise some of them at this point.
