Marine Landscaping

I need to remove tall sea grass and fallen dead trees off of my water front property. Off the bank the sea grass goes out about 30' x roughly 80' in length and there are several down trees laying in the grass that need to be removed. I would think you would need some sort of tool to cut the roots underwater and then a chainsaw to cut the trees up. I'm not sure how deep the water is but it would probably require a wet suit or a small boat.