We have 2 of those on my home lake.
They do an adequate job of cutting weeds down to about 8 feet. They mainly cut paths from your dock to the open water and then try to cut as much of the overgrown weeds down as possible. Only problem for me is the prevailing wind is from the west and my house is on the east shore. I get to rake up all the clippings that fall overboard, along with all my neighbors. We usually put a younger person aboard to throw back all the gamefish that get brought aboard during harvesting. You'd be surprised at the number of small bass and panfish that are buried in the thickest weeds. Local farmers take all we can give them as fertilizer.
Probably the best method for smaller waters.
Chemicals are not good, no matter what anyone says. We tried that some years ago, against many objections, in one portion of the lakes. Signs were posted "no swimming for 1 month and do not eat fish caught for 3 months". And this was a "safe chemical' if I recall. In larger bodies of water where the chemicals can disperse more, they might not be such an issue. If I recall, Aquacide and Sonar were tried. On a side note, a group of homeowners killed a huge expanse of bullrushes in front of their homes which have been there for years, eliminating one of my most productive spots. The lake specific rules clearly stated that emergent weeds such as bullrushes, lilypads, etc, are not to be removed. Not much you can do after the fact.
