Ive been twice as a photographer with a housed DSLR and would not use a reef hook. I have used them in Palau and even brought one on the first Galapagos trip, never left the dive locker.
My reasons:
- You would primarily be using them at Wolf and/or Darwin. You don't need a hook there. Wolf is easy, its a long sloping rocky ledge with lots of rocks and boulders. All you need to do is get behind a rock down current or wedge your knees between two rocks, both hands will be free. Darwin is a little more exposed, especially at the platform, but there are still areas where you can shelter, I found plenty of them. The platform is only one of several areas at Darwin to watch the show.
- Hammerheads are shy. You have to be down low and behind the rocks if you want any close pass bys. Even for schooling sharks, they will stay further away from the rocks of you are in the water column. Look at the pic of the Palau reef hook diver. The way you use a hook is to inflate your BC a bit. I would be royally pi**ed if someone was behind or near me floating in the column like that. Pretty much guarantees not very good hammerhead action.
- Whale sharks - whale sharks may come over the reef, more commonly they are swimming in the blue, into the current. Protocol is a DM will bang his or her tank, you pop off the wall and swim with the WS as long as you can. Back to the wall if you can get there. If you have to mess with deflating your BC, puling to the hook, unhooking... we're all gone with the WS, you're still on the rocks. (Yes, I've used them, so I know what it's like to hook/unhook) Trust me, when you hear the tank bang, you want to be off the wall ASAP.
- Sharks swim into the current. You face into the current floating on a reef hook. You want to shoot the sharks head on, or from the side, but the sharks will be coming from your rear. My experience in Palau was that turning to face the sharks as they came upcurrent was difficult at best, and it's mask off time if you turn into a strong enough current, making it potentially dangerous. the current shown in the Palau pic is up over the reef, currents in Galapagos (in my limited experience, 14 days total at Wolf and Darwin) are primarily along the reef.
- Galapagos can be extreme diving in fairy low vis (at least in September). The group will be (shoud be) spread out cross the reef. If I am in a ripping current, I want to have full control at all times to react to any situation. Reef hooks remove that ability. It's a bit different than in Palau with 100 foot vis and the group is more or less together.
-Galapagos is not the place to try out new skills, or skils learned from a video. Please take no offence, but you've got less than 100 dives. You may be a great diver, but trust me, the Galapagos is not the place to try out new skills unless you are very very competent, relaxed and proficient underwater.
All just my humble opinion