Collecting soil samples in estuary and wetland

There are many methods to collect soil samples in different environments. One can collect soils in forests, estuaries, wetlands, and even deep ocean. I would like to share some methods I have used in estuaries and wetlands.

The box corer shown below is very light (~10 kg) and can be used in a small boat. Having a pulley can be useful if we collect many samples but mandatory at all.

Left: soil box corer which is made with PVC material. It's great for collecting a small amount of soil from shallow-to-mid water depths.
Right: Gigantic coring device. We can collect a huge amount of soil from the deep oceans.
Middle: soil samples that were sub-sampled from the box corer.

Coring device made with PVC pipe

I find that collecting soil samples in wetlands is a lot simpler but more difficult because there are  roots. The PVC coring device is simply made with 10cm diameter PVC pipe attached to a flange (handle). We also need a locking plug which creates a suction to prevent soils falling out of the pipe.