I've hunted in swamps quite a bit, but I've always drawn the line on going into the stuff that's so flooded that you can't cross without risking swimming. I've crossed logs and beaver dams a few times, and I've gotten closer than I'd like to getting hypothermia a couple of times...
All that said, I'd say that (especially on public land), swamps are probably the best opportunity for a person of limited means to get themselves into superior deer hunting situations, since they keep lots of folks out. The last 2 clubs I was on both had swamp areas, and they were the only places I could be 99% sure of not seeing another person.
The hunting sled suggestion is a good one, although most of them may not hold an entire large buck inside without potentially swamping (but 100lbs is do-able, for sure). The problem USUALLY is getting the hunter out, not the deer
I have a sled for duck hunting, and it's fantastic when dealing with everything except cypress knees (or other uneven surfaces that you can't slide over).
If you have a reliable water channel to access, an inflatable raft might be an option for a creative hunter, but I've personally never been brave enough to stake my ability to get out of the woods on something that requires inflation (and no punctures) to get out. Another option, if you have an easier walk to water access points, is getting a lightweight kayak or canoe with one of those wheel attachments to roll it to the water. I've had an opportunity to use one of those in a couple spots, but most of the time getting TO the water is half of the problem.
My best spot ever was about 300 yards of woods and blowdowns to get to a big deep slough, with great hunting on the other side (food trees, travel funnel, and the only clearings on the property where you could see more than 30-40 yards. In that spot, I basically just hunted it until the heavier rains came, which could be early or late in the season. Once I couldn't get into the spot by walking in, I quit going. The deer were still on the other side, I just didn't have a good/safe way of getting to them.
Be creative, but be safe. Please try to avoid getting tunnel vision and doing something crazy just to get across a body of water. If you try something more "aggressive", then have a fail-safe plan, such as a rope and some emergency flotation on a rope so you can get back across.