The Crater is interesting for about one dive. It is like a 60' deep cylinder with very warm water. The operators have hung up a wagon wheel, and couple other odds and ends or there would be nothing to see in there.
The skiing here in Utah is great, diving, well, if you have dove around the world in salt or fresh water nothing here is too great at all, especially the Crater or Bonneville Seabase (another poor site).
So my advice, come here for the greatest snow on earth. If you want to break up your trip drop by the crater, rent some gear and get wet for an hour. Don't worry about dive computers, fish id cards, etc.
Utah is a great place to visit, ski, mountainbike, hike, etc.. Diving, well that is why I travel to your neck of the woods.
Dave