[Walter]

Unless you are very familiar with the site (it doesn't sound as if you are) retracing your steps is a very good idea. Instead of starting your dive under the boat, start it at the anchor. You should be able to recognize it on your return.

It is likely (although I don't know where you are diving) that there are recognizable features at your dive site, but you've yet to learn how to distinguish them. When we first start to explore underwater, we are like the city boy in the woods for the first time - everything looks the same. There are lots of differences, but we need to learn to see. Also, things often look different from the other side, turn and look behind you from time to time, so you will know how the features will look on your return trip. Keep in mind your depth. If you see a landmark at 60 ft and think you see it on your return at 40 ft, it's not the same feature.