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.
|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.