When diving in strong currents you basically only have two choices.
1. simply drift in the current with your dive buddy. 2. Enter the current and either hang on to a rock or use a reef hook as to make an anchor point.
Another option is to dive the lee of an island or reef and swim to the edge of the current line where the lee finishes.
A couple of things to keep an eye out for when approaching a current line from the lee of an island or reef. I have found that paying close attention to surrounding bait fish i can determine the direction of a current or current line that i am approaching. If all the bait or majority of are swimming in one direction it is a good indicator of what way the water is moving. Also air bubbles from wave wash or scuba divers will also indicate the direction of water movement.
A few months ago i was diving with a group at an off shore island. As we entered the water we noted that the currents appeared almost nil. During the dive we swam past a vertical wall reaching from the surface all the way down to 34m. The visibility was around 30m and off in the distance i noticed that all the bait close to the wall appeared to be swimming fast in an upward direction. Before we realised the entire group was forced by the water onto the sea floor. What had happened was a strong current in the top 10m or so of water was hitting the vertical wall and had created a down current, that was the reason for the fish to be swimming in an upward direction plus the reason that 6 scuba divers were pinned to the sea floor. All was fine as all the divers relaxed and assessed the situation, we moved out from the current and into the lee of the island out of the strong currents. In hindsight we should have noticed the direction of the bait swimming and could have simply adverted the situation. Always pay attention to your surroundings.
Things that i have found to be a good idea when diving in or around currents. Always dive with your buddy, pay attention to your buddy. Pay close attention to your SPG submersible pressure gauge and also your Non decompression limits on your dive computer. Use a safety sausage as it is almost impossible to spot a diver without one in choppy seas even form 50m away. If your after photos of large fish, current diving is the only way to go just be safe and dive within your limits.
Happy Diving Simon