Cutting the weeds is relatively easy (underwater weeds). Removing the weeds from the body of water will be the trick, and the supporting equipment needed to do that.

Underwater sickle mower https://www.lakemower.com/store/jenson-lake-mower-hd5000

Some weeds will reproduce from any fragments that are left in the water, so you have to know what weeds you can or cannot cut.........

https://aquaticweedharvester.com/about-us/

https://lakeweedharvester.com/eco-harvester/