Advanced Diving, as Stevo26 demonstrates his awareness, is not simply the ownership of that so-named c-card!
Advanced diving is any new situation, task or problem that a diver must deal with, after having whatever training they may.
In Truk, certainly the greatest new challenge to all is the extreme depths. The currents and your exposure to them will be well managed by the DM's, I would put that pretty low on the list.
There are a specified list of wrecks that are quite a bit shallower, but in that this is the case, they are much less recognizable as ships due to wave action, salvage destruction for navigation, and coral growth due to being higher in the phototropic column.
Another very large hump for many people is the utilization of small boats for diving and recovery. Backrolls are fairly quickly learned for most, but the "getting back in" or recovery takes a bit of paying attention and learning. The ability to manage "your space" is high on the list of skills. The boats get pretty tight!
Nitrox (as it is defined) is fairly well irrelevant for diving at Truk, the MOD for something as lightweight as EAN32 is 110 ft. (That's where you croak)
If talking about utilizing
specialized mixtures as a "travel gas", you could easily categorize that as "advanced". Probably
.1% of the divers who read SB would be currently & properly trained for this skill. Most all operations will absolutely specify precise depth limits, times, and ascent stages. They will place air and other mixtures at these stops. Many inexperienced recreational divers have survived this relying on blind faith, but it would likely be better if you understood the process well.
Truk dive ops have been hosting divers of all abilities, the great majority or them are still a threat to themselves and others at the point where they can afford the cubic, metric dollars to fly there and pay the fees.
A nice description of the most popular dives:
http://www.scuba-safaris.com/scuba-diving-locations/truk/dive_sites.html
The liveaboards are greatly preferred by most English speaking visitors, and unfortunately that is where you will see the most control exercised by crew over the participants due to our litigious reputation. Truly advanced divers who are fully ready to do this usually charter on with one of the land based dive ops. (
http://www.truk-lagoon-dive.com/)
Countless vacationers from the US who have thrown down for the price of a used Toyota have come home from Truk, with glowing stories. (And of course, the omnipresent digital camera images)
Here is a well written trip report:
Diving Truk on the Truk Aggressor II and
http://www.petemesley.com/truklagoon2008.htm