Look at driveway/gravel rakes. They're called different names, but they're 36" rakes available at most big box stores. Lowes calls them landscape rakes. They're much cheaper than "pond" rakes, and you can add noodles to the back to float it if needed. The only issue with them is that some have teeth on the tips, and that may make clearing the rake of weeds difficult. I just cut those off of mine.

Giant Salvinia? Let the plants dry out on the shore, then burn them if possible. If burning is dangerous in your area, then just make sure you dispose of it as far from standing water as you can.

AL