In this newly updated 7th edition of his Commercial Diver Training Manual, Hal Lomax has once again demonstrated his attention to detail and continued desire to make a maximum contribution to the education and safety of the commercial diver and the commercial diving industry. Those “old salts” and “young studs” involved in commercial diving can only benefit from the lessons contained in this manual; lessons learned the hard way from a man who is truly the divers’ friend. Hal continues his personal participation in our industry both topside and in the water. He continues to train (and retrain) both young and old divers. He knows the ins and outs as well as the fears and the exuberance of diving into the waters of our planet and, most importantly, knows and writes down the guidelines necessary to promote and retain safe commercial diving operations. In this manual he offers up tables, regulatory information, and industry practice. A responsible diving contractor should necessarily know the contents of this important work of dedication and should ensure that divers under his employ study and follow this importance guidance. To follow the guidance furnished in this important work will contribute to keeping you, the diver, and you the employer, out of harm’s way. In doing so, you will set an example for those with whom you work or employ. The waters where underwater operations take place are, and will remain, safe and welcoming as long as you plan the dive, work the plan, and continue to become better educated and aware of the hazards that may present themselves prior to or during the dive. This manual is one that should be in every dive locker.