Hammerhead situation at Wolf and Darwin is interesting. At the high season of November, during our safari, we had hundreds of them on every dive - above, below, on sides - everywhere. But due to very limited visibility and very dark ambient light conditions it is impossible to make any pictures - unless you are 2-3 meters away from the school, which does not happen often. From 5 dives we did on the Wold island I have just 5-6 ok pictures with hammers - far cry from that I was able to achieve in Cocos Island. Comparing my experience with experiences of others I concluded that Cocos Island is more productive place for predatory sharks photography then Wolf and Darwin - we had 15-20 meters viz and it was possible to make good pictures even with subjects outiside of the reach of strobe light. Of course I'm sure that if one spends couple of weeks or more in Wolf and Darwin - opportunity for good picture will present itself, but safari boats are allowed to stay only for three days at this remote islands. In Cocos you can spend week or even ten days. Both places are fantastic, it is just Cocos looks like little bit easier for photo. I will post more photos of hammers from last trip to Galapagos soon !