Our task is to design and build an aquatic weed removal system.
Maybe start by defining weed removal. Like esshup said, "mowing" the weeds can be simple, removing them will be the tough part. Are you looking to build a system that will need to be used on a regular basis (giving the weeds a haircut, with full intention of them growing back), or looking to completely eradicate/uproot/kill off the weeds? I'm guessing the former, and not the latter.
