Upload & Sell: On
Nice setup! You're right, of course, there's a big difference between protecting gear around the water, and actively shooting from a protective case or bag. I generally use the dry bags for getting gear to and from a site. On site, I generally take the gear out once (usually two camera+lens sets), and put them away when the shooting's done, or if we're doing a move that might be messy.
On dry land, I recently switched from using a "real" day backpack for events and travel, to a Think Tank Airport Commuter, because it's so difficult to "operate from" a toploading backpack. The TT is great. I mention this here, because I plan to take the TT to Labrador later this year, and there will be a lot of transportation in small boats, but not much shooting from small boats. With this in mind, I recently (yesterday) bought a MEC Slogg Deluxe 70 Dry Pack to hold the TT Airport Commuter. It's a combination of a large and very rugged dry bag with a high-quality backpack harness & strap system. There's even room for extra stuff!
MEC Slogg 70 http://www.mec.ca/product/5030-380/mec-slogg-deluxe-70-dry-pack/?f=10&q=slogg
Earlier, I briefly mentioned my "home made dry bag with a DIY "port" in the bottom". I didn't say much more, because there was enough going on, but I thought I'd say a bit more now, since the thread is back on its feet.
About ten years ago, I made a DIY "camera-clamp" dry bag using a SealLine clear dry bag, it's probably 20L capacity. I put a viewing port in the bottom of the bag, with an internal clamp gizmo that clamps onto a 77mm step ring at the front of the lens. It works well with a small body and zoom lens with a 72mm or smaller front thread, like the Tokina AT-X 24-200/3.5-5.6 and Tamron SP 28-75/2.8. I used it a couple of years ago with a 24-105L (77mm filter thread), but it needed a sequence of step down and then step up rings, to provide the 77mm step ring that gets clamped. Of course, this caused vignetting from about 30mm and wider, because the front element was too far back from the viewing port.
The clear dry bag lets you see all of the controls, and it quickly softens-up enough to use them, including even lens barrel switches (with a decent thumbnail). Push-pull and extending zoom lenses work best in this bag, as you just grab the front and pull or push to get the desired focal length. Overall, it worked very well. I can even completely submerge it, to get underwater shots in shallow water. It's not good enough for sustained immersion, but it's never had a leak in many years of kayaking, often in very wet conditions (i.e. waves). When not in use, it sits on top of my "deck bag", just forward of the cockpit, and so it gets lots of splash.
About six years ago, I moved to lenses with larger front diameters (i.e. L-zooms), and so the clamp system is too small. For the last few years, I've occasionally used an Olympus XP-1 with Oly waterproof case. It's a bombproof solution and great for skin diving, but it's really not good enough for what I want to do from my kayak. I think I'll make a larger camera-clamp dry bag this year, for an 86mm step ring. That'll fit anything with a 77mm front filter thread, and probably 82mm, as well. Too bad I sold my 28-300L to Larry, a couple of years ago.
The two photos below show the outside and inside of the kayak camera-clamp dry bag, Mk I. I'll post a DIY photo-dialogue to document construction of the Mk II that I'm planning to make.
Stay warm and keep dry, Jim