A lake mower is a boat-mounted machine which uses two sets of reciprocating blades to cut lake weeds and other aquatic plants under the surface of the water. The lake mower looks like an upside-down 'T' with the four-foot-wide cutter head below the water, the shaft mounted to a boat and an electric motor at the top.^[1]

The original lake mower was designed and patented in the mid 1990s by Ben Jenson who lived in Michigan, which is the "Land of 10,000 Lakes". Jenson then approached Dr. Johan Gervais, who was the director for a small business incubator in Texas, to market his invention.

A lake mower fits onto the front, transom, or side of a small boat and it is then used to cut the aquatic weeds underwater.^[2] The speed at which one can move through the water depends on the type and density of the aquatic plants, the power of the boat motor, and which type of lake mower motor is being used. lake mowers are sometimes used in conjunction with larger harvesters to get to more hard-to-reach or shallow areas of a lake.^[3]

Because it is mechanical and uses battery power some people have preferred using the lake mower over using herbicides due to environment reasons. Even those who are not opposed to using chemicals against unwanted lake weeds recognize the lake mower as a mechanical option in battling invasive species of aquatic weeds^[4][5][6][7] such as Eurasian milfoil.^[8]

A lake mower can be used with one of two electric motors: the regular one-tenth horsepower RG2500 or the stronger one-fifth horsepower HD5000. There are also several optional accessories which include:

• two-foot or four-foot extenders which extend the drive-shaft and thereby increase the cutting depth.
• a dedicated rake which is used to help clean away the cut weeds or other free-floating aquatic plants.^[9]

• Weed control
• Aquatic plants
• Aquatic weed control machines

• Josephson, Joan (September 19, 2008). "Bear Lake Property Owners Association lands $9,000 grant". The Observer. Dunkirk, New York. Retrieved 17 January 2010.