I'd take the good advice and go with a canoe or yak and carry it in with a dolly. I built a marshboat for duck hunting. The boat weighed about 100 lbs. I then built a dolly for it and now I can haul it around. Some places I used to hunt didn't have boat launches so I had to transport the boat 100 yards or so to water, the dolly worked great.

Transporting a canoe or yak that weighs under 50 lbs would be totally easy, even if the ground is a little rough.

Or, buy an old beater john boat and haul it in a leave it back there hidden someplace perhaps? I dunno, there are lots of options. What about an inflatable canoe/yak? Not the safest, but certainly safer than daggling you legs in the water like a couple of meat-sticks.

Plus, what if you did get bit back there? How far is it to safety? Gotta think about that worse case senerio and kinda plan for it ya know.