Hi the walk from where the ferry drops you off is about a block, possibly two, all uphill. The taxis are SO worth it!
The other negative of the excursion is the fast pace the tour sets. The last time we went which was on our own, we had 3 tour groups pass us up. It is true after the tour you can go and walk around on your own, but the resort is huge! You're going to be so beat after the tour you won't want to.
I don't know if this'll help or add to the confusion, but here is my cut and paste from what will ba an unofficial FAQ soon enough:
This note is for people who want to just go visit Atlantis and tour the Dig, a huge grouping of aquariums. If you want to use the water amenities(ANY water recreation on property), you need to get a room at Atlantis or Comfort Suites at Atlantis.
To just visit is very easy to do on your own. All you have to do is walk to the end of the dock, where there are numerous cabs(minivans) with a current rate of $4 per person to shuttle you over. There are also private limos if you prefer with competitve rates.
Where they drop you off at Atlantis is where they will pick you up to return to the dock. At this point you have access to the casino, the shops, the main building of the resort.
To get access to the Dig and all the resort, simply go to the center of the Casino to a kiosk with a blue globe over it.
Wristbands for access to the rest are $25 for adults, $19 for kids 4-12, Under 4 free. This is not for access to the water amenities, as I said above you have to get a room for that.
They will give you maps of the Dig/resort and such at that point. You're now on your own to explore the resort at your own pace. The Dig is in sections spread over the resort and it is a great deal of walking. But definitely worth it. Enjoy!
I also posted the above mentioned map with info here:
(click here) nassau excursion or not?