I am going to Antarctica in November for a photo trip but need a waterproof gear bag. Its main use will be for the transportation of my gear from ship to shore on the zodiacs. Has anyone done a similar trip (not necessarily to the polar regions but in wet environments) and can recommend anything to me?
I am very happy with Ortlieb bags. Ortlieb offers simple sacks, travel bags and backpacks in different sizes. They are 100% waterproof and if not overloaded, the bags will even swim on water.
I've used the Lowe Pro Dry Zone on several kayaking trips. Offers good protection as well as water proof. Not the easiest to access and not as large as I would like.
For a dry bag of some sort that you can put your main gear bag in for transport, the bags that are used for river trips can work well. I have experience with the roll up seal type bags, which work very well, and that is all that was used by the guides and by my self for my trip down the Colorado in the Grand Canyon. The link to Ortlieb bags that was shown above seems to feature the roll top type of bag, and that website is much closer to you than a US company would be. My bags came from a company called Cascade Outfitters, and here is a link to some dry bags: http://www.cascadeoutfitters.com/index.cfm?fuseaction=category.display&category_id=117&framein=
The Watershed bags listed in other links above use a little different closure, kind of like a Ziploc" bag, and those probably are fine, but I have no experience with them. The classic roll up seal has been in use by the military for many many years, and there is basically nothing that can go wrong with it. It just take a little more time to close, but not much more. But I do see that Cascade Outfitters also lists the "Ziploc" type bags now.
One issue is that many dry bags have a smaller opening at the end of a longer bag, and that small opening can make it very difficult to get a camera gear bag or small camera backpack in to the dry bag. If you want your whole camera gear bag to go in the dry bag, look for a bag that has a larger opening along the long dimension of the bag, rather than having a smaller opening at the end of the bag.
I set up my "day bag" with a shoulder bag for my gear, and then put it in to a dry bag so that I could access my gear easily. It became easy to un snap the end attachments and un roll the bag to get a camera out, and then stow it quickly before the next big rapids. I have not done an Antartic trip yet, but I am very sure you will want to take shots from the Zodiac part of the time. Of course when we got off the water and went on land hikes, I just removed my shoulder bag from the dry bag and used it normally.
Roland makes a good point, when you are on the water, whatever bag you use it is vital to have easy access to your camera. When I'm mobile on water I'll use the Dry Zone only for transport as it is too difficult getting gear in and out quickly. Once open you also expose everything in the bag to a rogue wave.
I use a dry bag with the zip lock type closure and have it open most of the time, it carries a D3 size body with a zoom of choice. There are several makes and can be found at nearly any kayaking retailer.
One of the posts above mentions that a wider opening and shallower bag is more convenient than the deeper bags with smaller openings. I just ordered a Dakine dry bag duffel exactly for this reason. Just received it, and though I haven't actually used it it appears like it will last. No padding really. For gear that I carry and need quick access to, I have used a Dri-Safe Out Pack (large size). It fits well for a 7D with a 15-85 (or 17-55) and 70-300L, but that is right at the limit. A larger camera would not fit well, and it's not good for a 70-200 2.8. Waterproof with some padding.
Chris - I've been using these bags for many years for my kayaking trips. They are reasonably priced and last a long time. I have many a time seen them dragged over rocks that I wish weren't, (kids). They offer no protection for your gear from hits, drops, and rocks, so you need to have your gear in a camera case that offers protection.
I bought my first one in 1987 very similar to what they offer today and it went on a trip this fall, not too bad.
There will be moisture in these bags from time to time depending on the weather conditions, there are many moisture absorbing products on the market, I always have one or two in each bag.
I was planning on putting one of my normal/usual backpacks inside one of these waterproof packs for the zodiac portions of the trip. I've currently got a few waterproof bags of various (smaller) sizes that have served to protect my camera gear on Colorado River rafting trips, though none have a shoulder harness. I only mentioned these bags for the specific reason that I am aware of other people that have taken an Antarctic trip have recommended these bags for the ease of transitioning into and out of zodiacs.
That said, the bag needs a large enough opening to easily access a pack like the Gura Gear Kiboko, or other similarly large camera pack as many photo ops present themselves from the zodiac. As I understand how the zodiac landings happen, camera gear needs to be stowed in the waterproof pack.
