Here are my mechanical tools at the moment. It's backbreaking work, so I only do a couple loads each day. Some patches of FA are far away and require chest waders to reach.

The drag is the "Yard Glider" that is relentlessly in my FB feed. I pulled the trigger and bought the basic model. Pricey, but heavy duty, and perfect for this application. Good for loading and unloading heavy mats of algae - no lifting and water drains right off.

[Linked Image from i.imgur.com]