This is a interesting topic and is an important consideration for those of us the sail in locations where bottom growth presents a real and aggravating condition we have to deal with. I refer to this growth as "moung". Over the years the primary place I sail has had significant issues with "moung" especially during the summer months. Until the past few years we've had to deal with our larger boats getting snagging by the "moung" to the point of needing a rescue boat be dispatched to pull or push the yachts free of the "death grip" the growth has on the keels.
These lakes are actually golf course lakes and managed by the crews that maintain the course. After years of our complaining they started adding a nontoxic dye to the water that filtered out much of the sunlight that provided life to this horrible growth. They only have to use it during the summer as the "moung" doesn't grow during the cooler times of the year.
The water has a blue tint to it now, doesn't hurt the fish and has cured the problem. It rinses off the boats and leaves no stain. I have no idea of what it is but, I'm told it is expensive. The golf course is private -for property owner's use only - so I guess that is why the course manager helped us out. I am pretty sure it helps having a few of the Board of Directors of the Association in our sailing group
It would be sad to have to limit our boat choices due to the bottom growth issue. I enjoy pretty much all the designs and being able to sail without that limitation any more. Fortunately the other lakes I frequent are pretty deep and bottom growth has not yet been an issue.
I have developed the habit of bringing a rescue craft along with me just to be prepared should I get stuck in the middle for some reason. In a previous post, I have shared a few photos of a few of my favorite rescue methods some in fun but my most faithful boat is a Coast Guard Motor Life Boat. As in real life and now in a much smaller scale the Coast Guard is here for us.
It has twin 550's which provide all the torque one could ever image needing for these kinds of rescues.
Having a rescue boat is a very good reason to get another boat too!