[laminar]

One addendum to Eric's advice: slow down a bit. Staying vertical while you have to equalize and kick and decide when to turn around and equalize your mask and stay relaxed can be very hard.

Make sure you are well weighted for the depth you are attempting (so you're not fighting buoyancy too much) and ease up on the pace so you can have more time to sense your orientation.

Oh, and a neck weight does wonders. Two ankle weights on a single strap usually does the trick (3-4 lbs).

Pete