There are many skills in scuba to master. One of the most important, and one that often causes divers grief, is a lack of situational awareness. Even though the oceans we delve into are vast, we need to have awareness of what is immediately around us. Here is just a short list of some of the more obvious, but often violated.
Whether you are diving in the Emerald Sea or somewhere tropical, currents are a fact of life. And they will threaten that life if you are not prepared.
Before getting into an ocean environment you should be asking about Tides and Currents. If you are not familiar with them, then ask your local dive shop or consult local Tide and Current tables. There are even apps you can download to assist you. Even if you are prepared, sometimes Mother Nature will throw you a curveball anyway.
A lot of the great dive sites here in Puget Sound and up in British Columbia are only accessible by boat. As a Diver, you need to be well versed in boat etiquette when schlepping your gear on board the dive charter. Here are some helpful tips.
If you do nothing else in diving, you owe it to yourself and your buddy to be Rescue Diver certified. Here we kick it up to a whole new level. We teach you how to recognize signs of distress in a diver or yourself. How to respond to an panicked diver or recovering an unconscious diver. This is just the tip of the iceberg. Passing this class will boost you confidence and give you tools you will use throughout your dive career! 
Must be Adv certified to take this course and a current CPR/First Aid card. Maroon Rescue Diver Hat with Argonaut logo included when passed. Cost is $250.00, includes book & video. Class usually meets either Wed or Thurs evening for academics at 6:00PM, then a pool session on Friday or Saturday, Open Water dives on Sat and/or Sun mornings.
One of the many skills we must have, as Scuba Divers, is the capacity to evaluate conditions, ourselves, of the dive site before plunging into the depths, whether it is on the beach or from a boat (charter).
If you are a dive leader, this responsibility becomes exponentially more important as your buddy and/or your fellow divers are counting on your expertise.