Manual removal can be a great option for any aquatic invasive plant, but keep in mind that SSW can regenerate from bulbils or fragments, so you would need to be very careful to get the entire plant each time. If you leave anything behind, you will not have accomplished much. This could be quite challenging at 7-10ft deep unless you have SCUBA gear or use a diver-assisted suction harvesting (DASH) system. Snorkeling to 7-10ft deep for plant removal is doable but challenging.
However you do this, you must reach down into the sediments by a few inches to lift the plant from the bottom. This will lift the bulbils out and keep the main thallus (stem) of the plant from breaking under stress. Simply yanking the plant from the top will likely break the stem and leave many bulbils behind. SSW tends to grow in soft sediments, so reaching into the sediments to dislodge the plant/bulbils is usually not difficult.