I'm a base hog, so I bring most of my metals back to main base. But I usually have smelters or furnaces at "ferry harbours" so I only have to pack processed metal on the boat.

As for swamps, they lend themselves to building tree houses, which can spice up base building quite a lot. The hoe is also a useful tool, even if it's just to put poles in the ground for a slightly elevated base. Just keep an eye out for leeches damaging your structures if you build in water.